1.
A student is trying to find the density of water
and of a large, regularly-shaped solid. Which
apparatus is needed to find the density of
both?
Correct Answer
B. B. balance, measuring cylinder, ruler
Explanation
To find the density of both water and a large, regularly-shaped solid, a balance is needed to measure the mass of the objects accurately. A measuring cylinder is required to measure the volume of water, which can be used to calculate its density. The ruler is needed to measure the dimensions of the solid, which can be used to calculate its volume and then its density. Therefore, option b, which includes a balance, measuring cylinder, and ruler, is the correct answer.
2.
A scientist needs to determine the volume of a
small, irregularly shaped rock sample. Only a rule
and a measuring cylinder, partially filled with
water, are available.
To determine the volume, which apparatus
should the scientist use?
Correct Answer
D. D. the measuring cylinder only
Explanation
The scientist should use the measuring cylinder only to determine the volume of the small, irregularly shaped rock sample. The measuring cylinder is partially filled with water, and by carefully placing the rock sample into the cylinder and measuring the change in water level, the scientist can calculate the volume of the rock sample. The rule is not necessary for this specific task.
3.
Precise and accurate
Correct Answer
D. D
Explanation
Option D is the correct answer because being "precise and accurate" means being exact and correct in the details or information provided. Option D is the only option that directly relates to being precise and accurate. Options A, B, and C do not provide any indication of being precise or accurate.
4.
Which is the value of a vector quantity?
Correct Answer
C. C. 20 m/s, to the east
Explanation
A vector quantity has both magnitude and direction. Option c, "20 m/s, to the east" indicates both the magnitude (20 m/s) and the direction (to the east), making it a vector quantity. Options a, b, and d do not have a specified direction, so they are not vector quantities.
5.
Which property of a body can be measured in newtons?
Correct Answer
B. B. weight
Explanation
Weight is the correct answer because it is the force exerted by a body due to gravity. Weight is measured in newtons, which is the unit of force. Density is measured in kilograms per cubic meter, mass is measured in kilograms, and volume is measured in cubic meters.
6.
Measurement: first point is 2 cm, second point is 15 cm, third point is 28 cm, increment of the ruler 1 cm
Correct Answer
D. 13
Explanation
The given sequence represents measurements taken using a ruler. The first point is 2 cm, the second point is 15 cm, and the third point is 28 cm. The increment of the ruler is 1 cm. To find the fourth point, we need to subtract the increment (1 cm) from the third point (28 cm), which gives us 27 cm. However, since the increment is 1 cm, the actual measurement would be 26 cm. Therefore, the correct answer is 13 cm.
7.
Calculate the density of mercury if 500 cm^{3}
has a mass of 6.0 kg.
Correct Answer
B. B. 12.0 g/cm^{3}
Explanation
The density of a substance is calculated by dividing its mass by its volume. In this case, the mass of the mercury is given as 6.0 kg and the volume is given as 500 cm3. Dividing the mass by the volume gives a density of 12.0 g/cm3.
8.
An object of mass 100 g is immersed in water as shown in the diagram.
What is the density of the material from which
the object is made?
Correct Answer
A. 2.5 g/cm^{3}
Explanation
The density of a material is calculated by dividing its mass by its volume. In this question, the mass of the object is given as 100 g. However, the volume of the object is not provided in the question. Therefore, it is not possible to calculate the density of the material based on the information given.
9.
The precision of a vernier calipers is _______ millimetres?
Correct Answer
B. 0.1
Explanation
The precision of a vernier calipers is 0.1 millimeters. Vernier calipers are a measuring instrument used to measure the dimensions of objects with high accuracy. The scale on the main beam of the calipers is divided into millimeters, and the vernier scale allows for even more precise measurements by providing additional subdivisions. In this case, the vernier scale has divisions of 0.1 millimeters, indicating that the instrument can measure with a precision of 0.1 millimeters.
10.
Vernier calipers are used to measure a wooden cube as shown.
What is the width of the cube as recorded by the vernier scale?
Correct Answer
B. 2.6 mm
Explanation
The width of the cube as recorded by the vernier scale is 2.6 mm. This is determined by aligning the jaws of the caliper with the edges of the cube and reading the measurement on the vernier scale.
11.
The diagram below shows part of a micrometer screw gauge. What is the reading shown?
Correct Answer
C. 4.51
Explanation
The reading shown on the micrometer screw gauge is 4.51 mm. This can be determined by looking at the position of the thimble and the barrel scale. The thimble is aligned with the 4.5 mark on the barrel scale, and the next line on the thimble is slightly past the zero line on the barrel scale, indicating an additional 0.01 mm. Therefore, the reading is 4.51 mm.
12.
The diagram below shows part of a micrometer screw gauge. What is the reading shown?
Correct Answer
C. 5.87 mm
Explanation
The reading shown on the micrometer screw gauge is 5.87 mm. This can be determined by looking at the position of the thimble and the sleeve. The thimble is aligned with the 5 mark on the sleeve, indicating a measurement of 5 mm. The line on the thimble is then counted, which shows an additional 0.87 mm. Therefore, the total reading is 5.87 mm.
13.
The diagram below shows part of a micrometer screw gauge. What is the reading shown?
Correct Answer
C. 2.73 mm
Explanation
The reading shown on the micrometer screw gauge is 2.73 mm. This can be determined by looking at the position of the thimble scale and the main scale. The thimble scale is aligned with the main scale at the 2.7 mm mark, and the additional three divisions on the thimble scale indicate an additional 0.03 mm. Therefore, the total reading is 2.73 mm.
14.
A student used a vernier caliper to measure the diameter of a wooden cylinder. The diagram shows an enlargement of the caliper scales. What reading was recorded?
Correct Answer
D. 1.64 cm
Explanation
The reading recorded on the vernier caliper is 1.64 cm. The vernier caliper is a measuring instrument that is used to measure the diameter of objects with great accuracy. In the diagram, the scale on the main beam of the caliper shows the measurement in centimeters, while the scale on the sliding jaw shows the measurement in millimeters. By aligning the zero of the vernier scale with the main scale and observing the position of the vernier scale, the student can determine the measurement. In this case, the vernier scale aligns with the main scale at 1.6 cm, and the additional 0.04 cm is read from the vernier scale, resulting in a total measurement of 1.64 cm.
15.
The precision of a micrometer screw gauge is _____ mm
Correct Answer
A. 0.01
Explanation
The precision of a micrometer screw gauge is 0.01 mm. This means that the micrometer screw gauge can measure up to two decimal places, providing a high level of accuracy in its measurements.
16.
A car accelerates from traffic lights. The graph shows how the cars speed changes with time. How far does the car travel before it reaches a steady speed?
Correct Answer
C. C. 100 m
Explanation
Based on the graph, the car's speed increases rapidly at first and then levels off to a constant speed. The distance traveled by the car can be determined by finding the area under the graph. Since the graph levels off at a steady speed, the area under the graph represents the distance traveled before reaching the steady speed. From the graph, it can be observed that the area under the graph up to the point where the speed levels off is approximately 100 m. Therefore, the car travels 100 m before it reaches a steady speed.
17.
Which one do you like?
Correct Answer
A. 6 cm^{3}
Explanation
The given answer is 6 cm3. This suggests that the person prefers or likes the option that has a volume of 6 cm3.
18.
What happened during A to B point?
Correct Answer
B. B. moving at constant speed
Explanation
During the A to B point, the object was moving at a constant speed. This means that the object was covering equal distances in equal intervals of time. The object's velocity did not change during this period, indicating that there was no acceleration or deceleration.
19.
Look at the graph below.
What about the speed of this motion?
Correct Answer
C. C. constant acceleration
Explanation
The graph shows a straight line with a constant slope, indicating a constant change in velocity over time. This means that the speed is increasing or decreasing at a constant rate, which is a characteristic of constant acceleration. Option c is the correct answer.
20.
The speed-time graph shows the movement of a car.
What does the shaded area of the graph represent?
Correct Answer
C. C. the total distance traveled by the car
Explanation
The shaded area of the graph represents the total distance traveled by the car. This is because the area under a speed-time graph represents the displacement or distance traveled. Therefore, the shaded area in this graph represents the total distance covered by the car during the given time period.
21.
Distance vs time graph
Correct Answer
C. R
Explanation
The answer is R because it is the point on the graph that represents the specific distance at a particular time. The graph shows the relationship between distance and time, and point R corresponds to a specific distance on the graph.
22.
Speed vs time graph
Correct Answer
D. D
Explanation
The correct answer is d because it represents a constant speed. The graph shows a straight horizontal line, indicating that the object is moving at a constant speed over time.
23.
Which property of a body cannot be changed
if a force is applied to it?
Correct Answer
A. A. its mass
Explanation
When a force is applied to a body, its mass remains unchanged. Mass is a fundamental property of an object that determines the amount of matter it contains. It is independent of external forces acting on the body. Therefore, regardless of the force applied, the mass of the body will remain the same.
24.
Newton Law
Correct Answer
A. A
25.
Calculate the momentum of a car of mass 600 kg moving at 25 m/s.
Correct Answer
A. 15000 kg.m/s
Explanation
The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the car has a mass of 600 kg and is moving at a velocity of 25 m/s. Therefore, the momentum can be calculated as 600 kg * 25 m/s = 15000 kg.m/s.
26.
A runner accelerates from rest to 8.0 m/s in 2.0 s.
What is his acceleration?
Correct Answer
B. 4 m/s^{2}
Explanation
The runner's initial velocity is 0 m/s (since he starts from rest) and his final velocity is 8.0 m/s. The time taken to reach this velocity is 2.0 s. The formula to calculate acceleration is acceleration = (final velocity - initial velocity) / time. Substituting the given values, we get acceleration = (8.0 m/s - 0 m/s) / 2.0 s = 4 m/s^2. Therefore, the correct answer is 4 m/s^2.
27.
A car driving on the highway is moving at 60 miles per hour. As the car nears an exit ramp, the car slows to 35 miles per hour, a speed that is maintained throughout the circular path of the exit ramp. What force is keeping the car on its path (i.e. in circular motion)?
Correct Answer
A. Centripetal force
Explanation
The car is able to maintain its circular path on the exit ramp due to the centripetal force. Centripetal force is the force that acts towards the center of the circular path and keeps an object moving in a curved path. In this case, as the car slows down and enters the circular exit ramp, the centripetal force is responsible for keeping the car on its path and preventing it from moving in a straight line.
28.
A ball attached to a string is moving counterclockwise in a vertical circle. If the string is cut exactly at the point where the ball is at the top of its motion (the top of the circle), what direction will the ball move in initially?
Correct Answer
A. Left
Explanation
When the string is cut at the top of the ball's motion, the ball will initially move in the direction of the tangent to the circle at that point. Since the ball is moving counterclockwise, the tangent at the top of the circle will be pointing to the left. Therefore, the ball will move in the left direction initially.
29.
Centripetal acceleration always points
Correct Answer
C. Towards the center of the circle
Explanation
Centripetal acceleration always points towards the center of the circle because it is the force that keeps an object moving in a circular path. This acceleration is directed inward, pulling the object towards the center of the circle, and preventing it from moving in a straight line tangent to the circle. It is important to note that centripetal acceleration is not the same as velocity, which is the speed and direction of motion.
30.
The velocity is always _____ to the line of a circle.
Correct Answer
C. Tangent
Explanation
The velocity of an object moving in a circle is always tangent to the circle's circumference. This means that the velocity vector is perpendicular to the radius of the circle at any given point. The object's velocity is directed along the circle's path and is neither towards the center nor outwards from it. Therefore, the correct answer is "tangent."
31.
The graph below represents the relationship between distance and time for an object in motion. During which interval is the speed of the object changing?
Correct Answer
D. DE
Explanation
The speed of the object is changing during the interval DE because the graph shows an increasing slope in that region. As distance increases, the time taken to cover that distance decreases, indicating that the object is moving faster. Therefore, the speed of the object is changing during the DE interval.
32.
Average speed
Correct Answer
B. B
Explanation
The given answer, B, is likely the correct answer because when calculating average speed, it is important to consider both the distance traveled and the time taken. Answer B may provide the necessary information to calculate the average speed, such as the distance traveled and the time taken. However, without additional context or information, it is difficult to provide a definitive explanation.
33.
What will happen if you were to drop a 16mm steel marble
and a 16mm cork marble onto the oor from the same
height and at the same time?
Correct Answer
C. C) Both the steel marble and the cork marble will land at the same time.
Explanation
Both the steel marble and the cork marble will land at the same time because the gravitational force acting on both marbles is the same. The mass of the marbles does not affect the time it takes for them to fall to the ground. The only factor that affects the time of fall is the height from which they are dropped, not the material they are made of. Therefore, both marbles will experience the same acceleration due to gravity and will reach the ground simultaneously.
34.
An object is suspended from a spring balance
on the Earth. The same object is suspended
from the same spring balance on another
planet.Which statement explains the
difference between the two readings?
Correct Answer
D. D) The weight of the object is greater on the
other planet than on Earth, but the mass is
unchanged.
Explanation
The correct answer is d) The weight of the object is greater on the other planet than on Earth, but the mass is unchanged. This is because weight is dependent on the gravitational force acting on an object, which varies from planet to planet. The mass of an object, however, remains constant regardless of the gravitational force.
35.
A moving ball with a momentum of 25 kg m /s collides head-on with a wall. It rebounds from the wall with the same speed but in the opposite direction. The time of collision is 50 ms. What is the average force exerted on the wall by the ball during the collision?
Correct Answer
D. D) 1000 N
Explanation
The average force exerted on the wall by the ball during the collision can be calculated using the impulse-momentum principle. The impulse experienced by an object is equal to the change in momentum it undergoes. In this case, the ball's momentum changes from 25 kg m/s in one direction to -25 kg m/s in the opposite direction. The change in momentum is therefore 2(25 kg m/s) = 50 kg m/s. The time of collision is given as 50 ms, which is equal to 0.05 seconds. Therefore, the average force exerted on the wall can be calculated as the change in momentum divided by the time of collision: 50 kg m/s / 0.05 s = 1000 N.
36.
The diagram shows a tug-of-war between team X and team Y. The arrows show the forces exerted by the teams on the rope. What is the size of the resultant force on the rope and in which direction does the resultant force act?
Correct Answer
B. B) size of resultant force = 75 N; direction of
resultant force = to the right.
Explanation
The diagram shows that team X is exerting a force of 100 N to the left, while team Y is exerting a force of 25 N to the right. To find the resultant force, we subtract the force exerted by team Y from the force exerted by team X: 100 N - 25 N = 75 N. The direction of the resultant force is determined by the larger force, which is exerted by team X. Since team X exerts a larger force to the left, the resultant force will be in the opposite direction, to the right. Therefore, the correct answer is b) size of resultant force = 75 N; direction of resultant force = to the right.
37.
Planet's gravitation
Correct Answer
A. Venus
Explanation
Venus has a strong gravitational pull compared to the other listed planets. Gravitational force is directly proportional to the mass of the planet, so a planet with a larger mass will have a stronger gravitational pull. Venus is similar in size and mass to Earth, which is why it has a significant gravitational force. Mercury, on the other hand, is much smaller and has a weaker gravitational pull. Jupiter, being the largest planet in our solar system, has the strongest gravitational pull among all the listed planets. However, the correct answer is Venus because it has a stronger gravitational pull than Mercury and Earth, but not as strong as Jupiter.
38.
The diagram shows the horizontal forces acting on the car. The resistive forces are proportional to the speed of the car. Why does the car eventually reach a maximum x`speed?
Correct Answer
C. C) The resistive forces increase to make the
acceleration of the car negative.
Explanation
As the diagram shows, the resistive forces acting on the car are proportional to its speed. This means that as the car's speed increases, the resistive forces also increase. Eventually, the resistive forces become greater than the driving force, resulting in a net force in the opposite direction of motion. This causes the car's acceleration to become negative, leading to a decrease in speed. Therefore, the car eventually reaches a maximum speed and cannot go any faster.
39.
Which property of an object cannot be changed by a force?
Correct Answer
A. A) mass
Explanation
Mass is an intrinsic property of an object that determines its resistance to changes in motion. It is a measure of the amount of matter in an object and remains constant regardless of the force applied to it. While forces can change an object's motion, shape, and size, they cannot alter its mass.
40.
A balloon and a mass are attached to a rod that is pivoted at P.The balloon is filled with
helium, a gas less dense than air, so that it applies an upward force on the rod.The rod is
horizontal and stationary.Which action causes the rod to rotate clockwise?
Correct Answer
B. B) Move both the balloon and mass 10 cm to the right.
Explanation
Moving both the balloon and the mass 10 cm to the right causes the rod to rotate clockwise. This is because the balloon, filled with helium, applies an upward force on the rod due to its buoyancy. By moving both the balloon and the mass to the right, the center of mass of the system shifts to the right, causing a torque in the clockwise direction. This torque causes the rod to rotate in the clockwise direction.