1.
Which of the following quantities has the same dimensions as Kinetic Energy, 1/2mv^2?
Correct Answer
A. Mgh
Explanation
The quantity Mgh has the same dimensions as kinetic energy, 1/2mv^2. This is because both Mgh and 1/2mv^2 have the dimensions of mass times distance squared divided by time squared. In Mgh, M represents mass, g represents acceleration due to gravity, and h represents height. Therefore, Mgh is the correct answer.
2.
At what time is the particle at the position x= 3t^2 - 12t + 20 at rest
Correct Answer
A. 2s
Explanation
The particle is at rest when its velocity is zero. To find the time at which the particle is at rest, we need to find the time when the velocity function, which is the derivative of the position function, equals zero. Taking the derivative of the position function, we get the velocity function as 6t - 12. Setting this equal to zero and solving for t, we find t = 2. Therefore, the particle is at rest at 2 seconds.
3.
A car moving with a velocity of 15m/s accelerate uniformly at rate of 2m/s^2 to reach a velocity of 20m/s. The time taken and distance travelled are respectively:
Correct Answer
C. 2.5m/s and 43.75m
Explanation
The car is initially moving with a velocity of 15m/s and accelerates uniformly at a rate of 2m/s^2. The final velocity is given as 20m/s. To find the time taken, we can use the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time taken. Rearranging the equation, we have t = (v - u) / a. Substituting the given values, we get t = (20 - 15) / 2 = 2.5s. To find the distance travelled, we can use the equation s = ut + (1/2)at^2, where s is the distance travelled. Substituting the given values, we get s = 15(2.5) + (1/2)(2)(2.5)^2 = 43.75m. Therefore, the time taken is 2.5s and the distance travelled is 43.75m.
4.
All inertia frame of reference
Correct Answer
D. All of the above
Explanation
All of the statements mentioned in the options are correct explanations for the concept of "All inertia frame of reference." Inertia frames of reference are those frames in which Newton's laws of motion hold true without the need for any additional forces or acceleration. These frames do not accelerate and are in relative motion to absolute space. Additionally, the laws of mechanics are applicable to all inertia frames of reference. Therefore, all the statements mentioned in the options are valid explanations for the concept.
5.
The simple assumption that all possible reference frames moving with uniform velocity relative to one another are equivalent for the statement of laws of physics is called the_________
Correct Answer
A. Principle of relativity
Explanation
The principle of relativity is the correct answer because it states that the laws of physics are the same in all inertial reference frames. This means that no matter how fast or in what direction an observer is moving, the fundamental laws of nature remain unchanged. This principle was first formulated by Galileo and later expanded upon by Einstein in his theory of special relativity. It is a fundamental concept in modern physics and has been confirmed by numerous experiments and observations.
6.
Which of the following defines a local space in which the positions of other objects are then described
Correct Answer
C. Coordinates
Explanation
Coordinates define a local space in which the positions of other objects are described. Coordinates provide a system of reference that allows us to specify the location of objects within a given space. They consist of a set of values that represent the distances or angles from a fixed point or axis. By using coordinates, we can accurately determine the position of objects relative to each other in a specific reference frame.
7.
Galiliean invariance is also known as
Correct Answer
C. Galiliean relativity
Explanation
Galilean invariance refers to the principle that the laws of physics are the same in all inertial reference frames. It is named after Galileo Galilei, who made significant contributions to the development of classical mechanics. Galilean relativity is another term used to describe this principle, emphasizing the idea that physical phenomena are relative and independent of the observer's motion. This term highlights the fundamental concept that the laws of physics remain unchanged regardless of the observer's velocity or reference frame.
8.
The path through which projectile travels is called ___________
Correct Answer
D. Trajectory
Explanation
The correct answer is trajectory. In projectile motion, the trajectory refers to the path that a projectile follows through the air. It is the curved path that results from the combination of the projectile's initial velocity and the force of gravity acting on it. The trajectory can be described using mathematical equations and can be influenced by factors such as the angle of projection and the initial velocity of the projectile.
9.
A gun of mass 10kg released a bullet of mass 20g at a speed of 100m/s. Find the gun's speed of recoil
Correct Answer
B. 0.2m/s
Explanation
When the gun releases the bullet, according to the law of conservation of momentum, the total momentum before and after the event should be equal. The momentum of an object is calculated by multiplying its mass by its velocity.
Before the event, the gun and the bullet have a total momentum of 10kg (mass of the gun) multiplied by the unknown velocity of the gun. After the event, the bullet has a momentum of 20g (mass of the bullet) multiplied by 100m/s (speed of the bullet), and the gun has a momentum of 10kg (mass of the gun) multiplied by the recoil velocity.
By equating the total momentum before and after the event, we can solve for the recoil velocity of the gun. In this case, the recoil velocity of the gun is calculated to be 0.2m/s.
10.
A particle is launched such that its maximum range is 26.4m.What is the speed at which it is lauched
Correct Answer
B. 16.2m/s
Explanation
The range of a projectile is given by the equation R = (v^2 * sin(2θ)) / g, where v is the initial velocity, θ is the launch angle, and g is the acceleration due to gravity. In this case, the maximum range is given as 26.4m. Since the launch angle is not specified, we can assume it to be 45 degrees to maximize the range. Plugging in the values, we get 26.4 = (v^2 * sin(90)) / g. Since sin(90) = 1, we can simplify the equation to 26.4 = v^2 / g. Solving for v, we find v = sqrt(26.4 * g). Since g is approximately 9.8m/s^2, the speed at which the particle is launched is approximately 16.2m/s.
11.
Force that acts on a mass of 1g and gives it an acceleration of 1cm/s^2 is defined as
Correct Answer
C. 1 Dyne
Explanation
The force that acts on a mass of 1g and gives it an acceleration of 1cm/s^2 is defined as 1 Dyne. This is because the Dyne is the unit of force in the CGS system of units, where 1 Dyne is equal to the force required to accelerate a mass of 1 gram by 1 centimeter per second squared.
12.
____________ quantities are known to be independent
Correct Answer
A. Fundamental quantities
Explanation
Fundamental quantities are known to be independent because they are the basic physical quantities that cannot be derived from any other quantities. They are considered as the building blocks for all other quantities. Examples of fundamental quantities include length, mass, time, electric current, temperature, amount of substance, and luminous intensity. These quantities are independent and are used to define other derived quantities and units.
13.
Motion of object without a specific direction is
Correct Answer
D. Random motion
Explanation
Random motion refers to the movement of an object without any specific direction or pattern. It occurs when the object's motion is unpredictable and changes constantly. In random motion, the object moves in various directions and at different speeds, making it difficult to determine its exact path. This type of motion can be observed in the movement of particles in a gas or the Brownian motion of small particles in a liquid.
14.
A _______________ body is one for which the distance between any two points of the body remains the same when the body is translated or rotated
Correct Answer
A. Rigid
Explanation
A rigid body is one for which the distance between any two points of the body remains the same when the body is translated or rotated. This means that no matter how the body is moved or turned, the distances between all points on the body remain constant. This property is often observed in solid objects such as a metal rod or a wooden block, where the shape and size of the object do not change regardless of its position or orientation.
15.
A rock is dropped from a cliff that is 10m above ground level. How long does it take the rock to reach the ground
Correct Answer
B. 4.5s
Explanation
The time it takes for an object to fall to the ground can be calculated using the equation: time = √(2h/g), where h is the height and g is the acceleration due to gravity. In this case, the height is 10m and the acceleration due to gravity is approximately 9.8 m/s². Plugging in these values, we get time = √(2*10/9.8) ≈ 4.5s. Therefore, it takes approximately 4.5 seconds for the rock to reach the ground.
16.
____________ is the Head of Physics Department in Federal University Oyè Ekiti?
Correct Answer
A. Dr. Hammed Shakirudeen
Explanation
Dr. Hammed Shakirudeen is the correct answer because the question asks for the head of the Physics Department in Federal University Oyè Ekiti. Since Dr. Hammed Shakirudeen is the only option given with a title of "Dr." and the others are either listed as "Proffesor" or "Dr." without a specific department mentioned, it can be inferred that Dr. Hammed Shakirudeen is the head of the Physics Department.
17.
The meaning of frame of reference is _________
Correct Answer
D. Space
Explanation
The meaning of frame of reference is space. A frame of reference is a coordinate system that is used to describe the position, motion, and properties of objects in space. It provides a point of reference from which measurements and observations can be made. In physics, frames of reference are essential for analyzing the motion of objects and understanding their interactions within a given space.
18.
The speed of light is
Correct Answer
B. 3 x 10^8
Explanation
The speed of light is a fundamental constant in physics and is denoted by the symbol "c". It is approximately equal to 3 x 10^8 meters per second. This value represents the speed at which light travels in a vacuum. It is an important constant in various scientific calculations and is used as a reference point for measuring the speed of other objects or phenomena.
19.
The dynamics along with the problems without referring to toffee is force causing the motion of the body is
Correct Answer
C. Kinematics
Explanation
The correct answer is Kinematics. Kinematics is the branch of physics that deals with the motion of objects without considering the forces causing the motion. It focuses on describing the position, velocity, and acceleration of objects, as well as their trajectories and time dependence. In this context, the question is asking for the branch of physics that specifically deals with the problems and dynamics of motion without referring to any external forces or factors. Therefore, the correct answer is Kinematics.
20.
Total displacement covered in total time taken is termed as
Correct Answer
B. Average velocity
Explanation
The average velocity is defined as the total displacement covered divided by the total time taken. It represents the overall rate of change of position over a given time interval.
21.
An object is thrown with a velocity v= 5.0i + 8.0j in m/s. Find the time taken to reach the maximum height
Correct Answer
A. 0.82s
Explanation
The time taken to reach the maximum height can be found by considering the vertical component of the velocity. Since the object is thrown upwards, the initial vertical velocity is positive. The time taken to reach the maximum height can be found using the formula: time = (final velocity - initial velocity) / acceleration. In this case, the initial velocity in the vertical direction is 8.0 m/s and the acceleration due to gravity is -9.8 m/s^2. Plugging these values into the formula, we get: time = (0 - 8.0) / (-9.8) = 0.82s. Therefore, the correct answer is 0.82s.
22.
When the velocity of an object is doubled, its Kinetic Energy is
Correct Answer
C. Quadrupled
Explanation
When the velocity of an object is doubled, its kinetic energy is quadrupled. This is because kinetic energy is directly proportional to the square of the velocity. Therefore, when the velocity is doubled, the kinetic energy increases by a factor of four.
23.
When you look at the speedometer in a moving car, you can see the car's
Correct Answer
D. Instantaneous speed
Explanation
The speedometer in a moving car shows the instantaneous speed of the car. Instantaneous speed refers to the speed of an object at a specific moment in time. It is the rate at which an object is moving at any given instant. In this case, the speedometer provides the current speed of the car, allowing the driver to know how fast they are traveling at that exact moment.
24.
An object moves at a constant speed of 6m/s. This means that the object
Correct Answer
D. Moves 6m every seconds
Explanation
The correct answer is "Moves 6m every second." This is because the question states that the object moves at a constant speed of 6m/s, which means it covers a distance of 6 meters in every second.
25.
Suppose the position of a particle at time t, is given by the position vector, the derivative of the position gives
Correct Answer
A. Velocity vector
Explanation
The correct answer is Velocity vector. The derivative of the position vector with respect to time gives the velocity vector. This means that by differentiating the position vector function with respect to time, we can determine the rate of change of position, which is the velocity of the particle at any given time.
26.
A particle has an acceleration of 2x^3 + 3x^2 at t=2s, determine the velocity of the particle
Correct Answer
A. 16m/s
Explanation
The velocity of a particle can be found by integrating its acceleration over time. In this case, the acceleration is given as 2x^3 + 3x^2. To find the velocity at t=2s, we need to integrate the acceleration function from t=0s to t=2s. After integrating, we get the velocity function as (2/4)x^4 + (3/3)x^3 + C, where C is the constant of integration. Evaluating the velocity function at t=2s, we get (2/4)(2^4) + (3/3)(2^3) + C = 16 + 16 + C = 32 + C. Since the constant of integration is not given, we cannot determine its value. Therefore, the velocity of the particle at t=2s could be any value, and none of the given options can be determined as the correct answer.
27.
The force that keeps an object moving in a circular path is called
Correct Answer
B. Centripetal force
Explanation
Centripetal force is the correct answer because it is the force that acts towards the center of a circular path, keeping an object moving in that path. It is responsible for maintaining the object's acceleration and preventing it from moving in a straight line tangent to the circle. Centrifugal force, on the other hand, is a perceived force that appears to push objects away from the center of rotation, but it is actually a result of the object's inertia. Oscillatory force is not a recognized term in physics.
28.
The unit of angular acceleration is
Correct Answer
B. Rad/sec
Explanation
The unit of angular acceleration is rad/sec because angular acceleration measures the rate at which an object's angular velocity changes over time. Angular velocity is measured in radians per second (rad/sec), and since angular acceleration is the change in angular velocity per unit of time, it is also measured in radians per second (rad/sec).
29.
__________ can be defined as the summation of the mass of an object and the square of the perpendicular distance
Correct Answer
A. Moment of Inertia
Explanation
Moment of inertia can be defined as the summation of the mass of an object and the square of the perpendicular distance.
30.
The first postulate of Albert Einstein in special relativity states that
Correct Answer
C. All the laws of physics are the same in all inertia frame of reference
Explanation
The correct answer is "All the laws of physics are the same in all inertia frame of reference." This answer aligns with the first postulate of Albert Einstein in special relativity, which states that the laws of physics are the same in all inertial frames of reference. This means that the fundamental principles and equations of physics remain unchanged regardless of the frame of reference from which they are observed. This postulate is a foundational concept in understanding the behavior of objects in motion and the consistency of physical laws across different perspectives.
31.
Calculate the average angular acceleration rotating at an angle of 30° for 5s
Correct Answer
C. 6rad/s
Explanation
The average angular acceleration can be calculated by dividing the change in angular velocity by the time taken. In this case, the angle rotated is given as 30° and the time taken is 5s. To convert the angle to radians, we multiply it by π/180. So, the angle in radians is (30°) * (π/180) = π/6 rad. Now, we can calculate the average angular acceleration by dividing the angle in radians by the time taken: (π/6 rad) / 5s = π/30 rad/s. Simplifying this gives approximately 0.1 rad/s. Since the answer options are given in whole numbers, the closest option is 6 rad/s.
32.
The property of a body to remain at rest or to continue to move in a straight line, is known as
Correct Answer
D. Inertia
Explanation
Inertia is the property of a body to remain at rest or to continue moving in a straight line. It is the resistance of an object to any change in its state of motion. This means that an object at rest will stay at rest, and an object in motion will continue moving with the same speed and direction, unless acted upon by an external force. Inertia is a fundamental concept in physics and is related to the mass of an object.
33.
A resultant force of 15N acts on a body for 4s mass 4kg. Calculate the change in momentum of the body within this period
Correct Answer
A. 60Ns
Explanation
The change in momentum of an object can be calculated using the formula change in momentum = force x time. In this case, the force acting on the body is 15N and the time period is 4s. Therefore, the change in momentum is equal to 15N x 4s = 60Ns.
34.
A block of mass 10kg was moved by a force of 20N. Find the coefficient of Friction
Correct Answer
C. 0.2
Explanation
The coefficient of friction is a measure of the frictional force between two surfaces in contact. In this scenario, a block of mass 10kg was moved by a force of 20N. By using Newton's second law (F = ma), we can calculate the acceleration of the block. Then, by using the equation for frictional force (Ff = μN), where N is the normal force, we can solve for the coefficient of friction. Without additional information, we assume that the normal force is equal to the weight of the block (mass x gravity). By plugging in the values, we find that the coefficient of friction is 0.2.
35.
One remarkable consequence of relativity is that simultaneity of events and sometimes even their time order depend on one's
Correct Answer
B. Reference frame
Explanation
In the theory of relativity, the concept of simultaneity and the order of events can vary depending on the observer's reference frame. This means that two events that are simultaneous for one observer may not be simultaneous for another observer in a different reference frame. The time order of events can also be perceived differently by different observers. Therefore, the correct answer is "Reference frame" as it is the observer's frame of reference that determines the simultaneity and time order of events.
36.
A stone was projected with a speed of 8m/s at an angle of 15°, find its range (take g=10)
Correct Answer
B. 3.2
Explanation
The range of a projectile is the horizontal distance it travels before hitting the ground. To find the range, we can use the formula: R = (v^2 * sin(2θ)) / g, where R is the range, v is the initial velocity, θ is the angle of projection, and g is the acceleration due to gravity. Plugging in the given values, we get R = (8^2 * sin(2*15))/10 = 3.2. Therefore, the correct answer is 3.2.
37.
A girl is riding a bicycle along a straight road at constant speed at constant speed, and passes a friend standing at a bus stop (event 1). At a time of 60s later the friend catches a bus (event 2). If the distance separating the events is 126m in frame of the girl on the bicycle, what is the bicycle's speed?
Correct Answer
D. 2.10m/s
Explanation
The correct answer is 2.10m/s because the distance separating the events is given as 126m in the frame of the girl on the bicycle. Since the girl is riding at a constant speed, the distance covered in 60s is equal to the distance between the events. Therefore, the girl's speed is calculated by dividing the distance by the time, which gives us 126m / 60s = 2.10m/s.
38.
___________ is the physical entity that can be measured?
Correct Answer
B. Dimension
Explanation
Dimension is the physical entity that can be measured. It refers to the measurable properties of an object or system, such as length, mass, time, temperature, etc. Units are used to quantify these dimensions, while a force is a type of interaction between objects and a system refers to a collection of objects or components working together.
39.
A ball is projected at an angle of elevation of 60° with an Initial velocity of 100m/s^2, find the time of flight
Correct Answer
C. 17.32s
Explanation
The time of flight of a projectile can be calculated using the formula: time = (2 * initial velocity * sin(angle of elevation)) / acceleration due to gravity. In this case, the initial velocity is 100 m/s^2 and the angle of elevation is 60°. The acceleration due to gravity is usually taken as 9.8 m/s^2. Plugging in these values into the formula, we get: time = (2 * 100 * sin(60°)) / 9.8 = 17.32s. Therefore, the correct answer is 17.32s.
40.
The two postulates of Einstein is known as
Correct Answer
B. Special relativity
Explanation
The correct answer is "Special relativity". Einstein's two postulates, known as the special theory of relativity, are based on the principles that the laws of physics are the same in all inertial reference frames and that the speed of light in a vacuum is constant for all observers. These postulates revolutionized our understanding of space, time, and the relationship between matter and energy. The equation E=mc^2 is a consequence of special relativity, but it is not one of the two postulates.