3. Dynamics
A section of Physics, 9702
Listing 10 of 281 questions
Two blocks, of mass 0.20 kg and 0.50 kg, are connected by a light inextensible string that passes over a frictionless pulley. rough horizontal surface block, mass 0.20 kg block, mass 0.50 kg pulley The blocks are initially held stationary. The block of mass 0.20 kg rests on a rough horizontal surface. The block of mass 0.50 kg is suspended in air. Air resistance is negligible. When the blocks are released, they have an acceleration of magnitude 2.0 m s–2. What is the magnitude of the frictional force between the block of mass 0.20 kg and the rough surface?
9702_w23_qp_12
MCQ
2023
Paper 1, Variant 2
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A ball Y moves along a horizontal frictionless surface and collides with a ball Z, as illustrated in the views from above in and . Y Z P Q 0.25 kg mZ BEFORE COLLISION P Q 0.25 kg mZ AFTER COLLISION Y Z 27° 44° 3.7 m s–1 5.5 m s–1 (not to scale) (not to scale) Ball Y has a mass of 0.25 kg and initially moves along a line PQ. Ball Z has a mass mZ and is initially stationary. After the collision, ball Y has a final velocity of 3.7 m s–1 at an angle of 27° to line PQ and ball Z has a final velocity of 5.5 m s–1 at an angle of 44° to line PQ. Calculate the component of the final momentum of ball Y in the direction perpendicular to line PQ. component of momentum = N s By considering the component of the final momentum of each ball in the direction perpendicular to line PQ, calculate mZ. mZ = kg During the collision, the average force exerted on Y by Z is FY and the average force exerted on Z by Y is FZ. Compare the magnitudes and directions of FY and FZ. Numerical values are not required. magnitudes: directions: Two blocks, A and B, move directly towards each other along a horizontal frictionless surface, as shown in the view from above in . A B 4 m s–1 6 m s–1 The blocks collide perfectly elastically. Before the collision, block A has a speed of 4 m s–1 and block B has a speed of 6 m s–1. After the collision, block B moves back along its original path with a speed of 2 m s–1. Calculate the speed of block A after the collision. speed = m s–1
9702_w23_qp_22
THEORY
2023
Paper 2, Variant 2
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Questions Discovered
281