If the velocity of a particle is nonzero, can the particle’s acceleration be zero? Explain.

6. A ball is thrown upward with a velocity of 4.5 m/s. Its speed and the magnitude of its acceleration at the highest point (a) are both equal to zero (b) are given by 9.81 m/s and 0 m/s², respectively (c) are given by 0 m/s and 9.81 m/s², respectively (d) cannot be predicted unless the height is known Answer: 7. Which of the following statements about a projectile is not true? Assume that the air resistance is negligible. (a) Its motion is in two dimensions. (b) The only acceleration is in the vertical direction. (c) Its velocity in the horizontal direction remains the same throughout the flight. (d) The velocity at the highest point of its trajectory is zero. Answer:

A projectile is fired from point A at the edge of a cliff, whose initial velocity components are v0x = 60.0m / s and v0y = 175m / s. The projectile rises and then falls into the sea at point P. The projectile flight time is 40.0s and it does not experience appreciable air resistance in flight. a) Make a diagram of the problem, b) Determine how far it falls, c) what is the height of the cliff? and d) at what angle was it shot?

A certain volcano on the Earth can eject rocks vertically to a maximum height H. How high (in terms of H) would these rocks go if a volcano on a planetary object ejected them with the same initial velocity? The accelerations due to the gravity on the Earth and the planetary object are 9.8m/s² and 3.1 m/s?, respectively. Neglect the effect of the air on both planets. 답:

Captain Marvel jumps straight up in the air with a velocity of 30m/s straight up. She reaches a maximum height and then falls back down due to gravity to the same level. This is not a projectile question. a) what max height will she reach? b) How long will it take her to return to the same height from which she jumped c) What will her velocity be when she is just about to hit the ground at the same level she jumped from