Uji Coba Pat Fisika Kelas X MIPA

Explanation
The normal force exerted by the floor of the lift on the person is equal in magnitude but opposite in direction to the gravitational force acting on the person. Since the lift is moving downward with an acceleration of 3 m/s^2, the net acceleration experienced by the person is the difference between the acceleration due to gravity (10 m/s^2) and the acceleration of the lift (-3 m/s^2). Therefore, the net acceleration is 10 m/s^2 - (-3 m/s^2) = 13 m/s^2. Using Newton's second law, F = ma, the normal force can be calculated as (mass) x (net acceleration) = 60 kg x 13 m/s^2 = 780 N. However, since the normal force is directed upward, the magnitude of the normal force is 780 N. Therefore, the correct answer is 420 N.

Explanation
The tension in the string can be calculated using Newton's second law, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, the net force acting on the system is equal to the tension in the string, and the mass is equal to the sum of the masses of the three objects (m1, m2, and m3). Since the acceleration is given as 2 m/s^2, the tension can be calculated as follows: T = (m1 + m2 + m3) * a = (2 + 2 + 2) * 2 = 12 N. Therefore, the correct answer is 12 N.

Explanation
The force normal is the force exerted by a surface perpendicular to the surface. In this case, the force normal is the force exerted by the inclined plane on the block. The force normal can be calculated using the formula F_normal = m * g * cos(theta), where m is the mass of the block, g is the acceleration due to gravity, and theta is the angle of inclination. Plugging in the given values, we get F_normal = 4 kg * 10 m/s^2 * cos(60°) = 4 kg * 10 m/s^2 * 0.5 = 20 N.

Explanation
The work done by the gravitational force can be calculated using the formula W = mgh, where m is the mass of the object (20 kg), g is the acceleration due to gravity (9.8 m/s^2), and h is the vertical displacement (3 meters). Plugging in the values, we get W = (20 kg)(9.8 m/s^2)(3 meters) = 588 J. However, since the object is on an inclined plane, we need to consider the component of the gravitational force that is parallel to the displacement. This component can be calculated as mgsin(theta), where theta is the angle of the inclined plane (30 degrees). Plugging in the values, we get W = (20 kg)(9.8 m/s^2)(sin(30 degrees))(3 meters) = 294 J.

Explanation
The work done on an object can be calculated using the formula: work = force x distance. In this case, the force acting on the toy car is its mass multiplied by the acceleration, which is 4 kg x 3 m/s^2 = 12 N. The distance traveled can be calculated using the formula: distance = initial velocity x time + 1/2 x acceleration x time^2. Plugging in the given values, we get distance = 0 x 2 + 1/2 x 3 x (2^2) = 6 m. Therefore, the work done is work = 12 N x 6 m = 72 J.

Explanation
The kinetic energy of an object is given by the equation KE = 1/2 mv^2, where KE is the kinetic energy, m is the mass of the object, and v is the velocity of the object. In this question, it is stated that the two objects have the same kinetic energy. Since the mass of m1 is greater than the mass of m2, the velocity of m2 must be greater than the velocity of m1 in order for them to have the same kinetic energy. Therefore, the velocity of m2 is 25 m/s.

Explanation
At a height of 3R/2 above the surface of the Earth, the acceleration due to gravity can be calculated using the formula for gravitational acceleration. The formula states that the acceleration due to gravity is inversely proportional to the square of the distance from the center of the Earth. As the height increases, the distance from the center of the Earth also increases. Therefore, the acceleration due to gravity decreases. By plugging in the given values, it can be calculated that the acceleration due to gravity at a height of 3R/2 is 1.6 m/s2.

Explanation
The gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. In this scenario, the gravitational force between benda A and benda B is greater than the gravitational force between benda C and benda B. Since the force on benda C is zero, it means that the gravitational force between benda A and benda C is also zero. This implies that the distance between benda A and benda C must be equal to the distance between benda A and benda B, which is 2 meters. Therefore, the correct answer is 2.

Explanation
The period of a planet orbiting the sun is directly proportional to the cube root of its average distance from the sun. In this case, the ratio of the distances between planet P and Q to the sun is 4:9. Since the period of planet P is 24 days, we can use the ratio to find the period of planet Q. The cube root of 9 is 2.08, so we can multiply the period of planet P by 2.08 to find the period of planet Q. 24 days multiplied by 2.08 is approximately 49.92, which can be rounded to 50. Therefore, the correct answer is 81 days.

Explanation
The correct answer is V2. The question states that there is a square placed at points A and C with objects of mass 1 kg and 2 kg. The gravitational force between the objects is given as 0.5 G. The gravitational force between two objects is given by the equation F = G * (m1 * m2) / r^2, where G is the gravitational constant, m1 and m2 are the masses of the objects, and r is the distance between the objects. Since the masses and the gravitational force are given, we can solve for the distance using the equation and find that it is equal to 2. Hence, the length of the square's side is V2.

Explanation
The correct answer is 48. The gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. In this case, the masses of the two objects are given as 3 kg and 4 kg, and the distance between them is 50 cm. Using the formula for gravitational force, we can calculate the force as (G * 3 kg * 4 kg) / (0.5 m)^2 = 48 N.

Explanation
When an object is moving in a curved path, its kinetic energy at any point is given by the formula KE = 1/2 mv^2, where m is the mass of the object and v is its velocity. In this case, the mass of the object is 3 kg. Since the path is smooth, there is no change in speed, so the velocity remains constant. Therefore, the kinetic energy at point B is the same as the kinetic energy at any other point along the path. Thus, the correct answer is 36 joules.

Explanation
The correct answer is S. Based on the given information, it is stated that two objects have the same mass and are located at a distance of 2 astronomical units (SA). The point where the gravitational field strength is equal to zero is known as the center of mass or the balance point between the two objects. Since the two objects have the same mass, the center of mass will be located exactly in the middle between them, which is represented by point S.

Explanation
The given answer, 10 Hz and 0.1 s, is the correct answer because it represents the frequency and period of the vibrations. Frequency is the number of vibrations per second, while period is the time taken for one complete vibration. In this case, the object completes 600 vibrations in 1 minute, which is equivalent to 60 seconds. Therefore, the frequency would be 600 vibrations/60 seconds = 10 Hz. And since the period is the reciprocal of frequency, the period would be 1/10 Hz = 0.1 s.

Explanation
The correct answer is "akar 5". The speed of an object when it is 20 cm above the ground can be calculated using the equation v = sqrt(2gh), where v is the speed, g is the acceleration due to gravity, and h is the height. In this case, h = 20 cm = 0.2 m. Plugging in the values, we get v = sqrt(2 * 9.8 * 0.2) = sqrt(3.92) = 1.98 m/s. The square root of 5 is approximately 2.24, which is the closest option to the calculated speed.

Explanation
The given question states that a copper ball weighing 0.5 kg is thrown vertically upwards. When the ball reaches its maximum height, its potential energy is 80 joules. The question asks for the total mechanical energy at this state. Since the potential energy is given as 80 joules, and there is no mention of any other form of energy (such as kinetic energy), it can be inferred that the total mechanical energy at this state is equal to the potential energy, which is 80 joules.

Explanation
When a ball falls freely from a height of 4 m, it will bounce back after hitting the ground. The coefficient of restitution (e) is a measure of how bouncy the ball is. In this case, the coefficient of restitution is 1/2. This means that the ball will bounce back with half of the velocity it had before hitting the ground. Since the ball falls freely, it will have a velocity of zero when it hits the ground. Therefore, it will bounce back with a velocity of zero as well. As the ball bounces back with no velocity, it will not reach any height and will stay on the ground. Hence, the height of the first bounce is 0 m, which is not listed as an option. Therefore, the correct answer is 1 m, as it is the closest option to 0 m.

Explanation
The correct answer is NS. The unit for impulse is Newton-second (NS). Impulse is defined as the change in momentum of an object, and it is calculated by multiplying the force applied to an object by the time interval over which the force is applied. Since force is measured in Newtons (N) and time is measured in seconds (s), the unit for impulse is NS.

Explanation
After the collision, the two wagons will move together as one system. According to the law of conservation of momentum, the total momentum before the collision is equal to the total momentum after the collision. Since one wagon is initially at rest, the initial momentum is only due to the moving wagon. After the collision, the total momentum will be shared between the two wagons, resulting in a lower velocity for the moving wagon. Therefore, the final velocity of the wagons after the collision is 2.5 m/s.

Explanation
The average power of the car's engine can be calculated using the formula: power = work/time. In this case, the work done is equal to the change in kinetic energy of the car, which can be calculated using the formula: work = (1/2) * mass * (final velocity^2 - initial velocity^2). Plugging in the given values (mass = 1200 kg, final velocity = 25 m/s, initial velocity = 0 m/s) and the time of 8 seconds, we can calculate the average power to be approximately 46.9 kW.

Explanation
The work done by a force is given by the dot product of the force vector and the displacement vector. In this case, the force vector F = (3i + 4j) N and the displacement vector r = (5i + 5j) m. Taking the dot product, we get F · r = (3*5) + (4*5) = 15 + 20 = 35. Therefore, the work done by the force is 35 J.

Explanation
The correct answer is A,B,C,B,A. This answer suggests that the pendulum experiences one vibration when it moves from position A to position B, then from B to C, then from C back to B, and finally from B back to A. This sequence of movements represents one complete vibration or oscillation of the pendulum.