Question

(1)A perfectly elastic ball falls sideways on a smooth, stable surface and is reflected. The bead: a) maintains its momentum. b). after its reflection it always moves in a direction that is perpendicular to the direction of its original velocity. c) exerts on the surface a force that has the direction of the velocity with which it strikes it. d) retains its kinetic energy. choose the correct answer 2) A sphere A of mass m1 moving with speed υ1 collides centrally and elastically with a stationary sphere B of mass m2. The rate of change of the kinetic energy of sphere A depends on: a) from the time that the impact of the spheres lasts. b.) from the initial momentum of the sphere A. c). from the masses of the spheres .d) from the initial velocity of the sphere A. choose the correct answer (3)During the central and elastic impact of two spheres, the difference of their velocities before the impact is: a) greater than the difference of their speeds after the impact b) equal to the difference of their speeds after the impact c) less than the difference of their speeds after the impact d) opposite to the difference of their speeds after the impact choose the correct answer

Answer 1

Question 1.

Given that a perfeectly elastic ball falls sideways on a smooth, stable surface and is reflected. Let's determine what will happen to the ball from the given options.

Here, the ball is elastic. Since the perfectly elastic ball falls sideways on a smooth, stable surface and is reflected, the force the ball exerts is in the direction of its velocity.

Therefore, the ball exerts on the surface a force that has the direction of the velocity with which it strikes it.

ANSWER:

c) Exerts on the surface a force that has the direction of the velocity with which it strikes it.