Timmy the Astronaut stands at the edge of a Lunar cliff with two similar rubber balls. He throws the blue one upwards and the red one downwards, but throws them each with the same speed. After the blue ball passes Timmy, which of the following statements is true? A.The blue ball begins to catch-up to the red ball B.The distance between the two balls will remain the same C. The red ball pulls away from the blue ball D. Bogus! There's no way to know
A bowling ball is dropped from a building at the same time that a stone is launched upward from the ground. The initial speed of the stone is equal to the speed of the ball just before it hits the ground. The ball and the stone cross A) above B) exactly at C) below half the height of the building.
A stone is launched vertically up, its speed slowing under the influence of gravity. Suppose we film this motion and play the tape backward (so the tape begins with the ball at a high point and ends with the ball at a low point). A) What you see on the tape could never happen in reality. B) The tape shows the motion of a stone in free fall, but the acceleration is upward rather than downward. C) The tapes shows the motion of a stone in free fall with a downward acceleration g.
Two identical balls roll off a tabletop. Just before rolling off, one is rolling at 0.5 m/s and one is rolling at 1 m/s. Which ball hits the ground first? A) The ball with initial speed = 0.5 m/s. B) The ball with initial speed = 1 m/s. C) Both land at the same time.
Consider the following three items mounted on a platform: (A) A balance with a wooden block on one side and calibrated weights on the other, (B) A spring scale with a wooden block on it, and (C) A metal object suspended from a brass spring If the platform accelerates up, which of the following occur(s)? 1) The reading of the balance changes. 2) The spring scale reading changes. 3) The brass spring changes length. 4) All three. 5) 2 out of three.
A small rubber ball is put on top of a volleyball, and the combination is dropped from a certain height. Compared to the speed it has just before the volleyball hits the ground, the speed with which the rubber ball rebounds is A) the same. B) twice as large. C) three times as large. D) four times as large. E) impossible to estimate without knowing their masses
A student on a moving skateboard is holding a tennis ball and wants to release the ball so that it will hit a mark on the floor. The student is moving toward the mark. Where should the student be when he releases the ball? A) Beyond the mark B) Right above the mark C) Somewhat before the mark
A block of inertia m is attached to a relaxed spring on an inclined plane. The block is allowed to slide down the incline, and comes to rest. The coefficient of kinetic friction of the block on the incline is m k. For which definition of the system is the work done on the system negative? A) block B) spring C) incline D) earth E) none of the above
Consider a collision of two objects for which the coefficient of restitution e=1/2. Assume that one of the objects was initially at rest. During the collision, which of the following is true? The kinetic energy K of the two-object system before the collision is converted to: A) dissipated energy B) potential energy C) dissipated energy and potential energy D) source energy E) dissipated energy and source energy
You have a pair of inclined planes such that a block that slides down one can slide up the other without losing any energy in the transition. The inclined planes are both at angle a from the horizontal, as shown on the white board. The inclined plane on the right has a coefficient of friction with the block of m. The inclined plane on the left is frictionless. You can start the block sliding down either side at a height h. Which side do you start the block sliding down to have it slide the greatest distance up the other side? A) Right B) Left C) Need more information D) Same