2. 1D Motion / Kinematics

A pellet gun is fired straight downward from the top of a $50m$ tall building with an initial speed of $10m/s$. Ignoring air resistance, how long does it take for the pellet to reach the ground? (Take $g=9.8m/s^2$)

A ball is thrown from the edge of a cliff in three different ways: (A) straight upward with an initial speed $v>0$, (B) straight downward with the same initial speed $v$, and (C) horizontally with speed $v$. Neglecting air resistance, rank the throws from longest to shortest time for the ball to hit the ground.

During the vertical motion of a projectile, is the vertical component of velocity ($v\_y$) ever zero? If so, when does this occur?

An object is thrown vertically upward and reaches its highest point. Ignoring air resistance, what is its velocity $1$ second after it reaches its highest point?

Abby throws a ball straight upward with an initial velocity of $v_{0y}$. Ignoring air resistance, how high above her original starting position does the ball rise before coming to rest momentarily at its peak?

A $60kg$ rider is in an elevator that is in free fall. What is the rider's apparent weight during the period of free fall?

A small bag of sand is released from a hot air balloon that is ascending vertically at a constant velocity. Ignoring air resistance, what is the initial velocity of the sand bag immediately after it is released, relative to the ground?

When a bullet is fired horizontally from a rifle, at what point does it begin to fall toward the ground due to gravity?

Two identical balls are dropped from the same height at the same time, one from rest and the other thrown downward with an initial speed $v\_0$. Ignoring air resistance, which ball hits the ground first, or do they hit at the same time?

Which statement best compares the accelerations of two objects in free fall near Earth's surface (neglecting air resistance)?

The motor of a 350 g model rocket generates 9.5 N thrust. If air resistance can be neglected, what will be the rocket's speed as it reaches a height of 85 m?

In vertical motion under gravity, how does the vertical acceleration at point $A$ compare to the vertical acceleration at point $C$ along the trajectory of a freely falling object (neglecting air resistance)?

(I) If a car rolls gently (v₀ = 0) off a vertical cliff, how long does it take it to reach 55 km/h?

A person holds a bill of length $16cm$ vertically above her hand and releases it from rest. Assuming negligible air resistance and that the acceleration due to gravity is $g=9.8m/s^2$, approximately how much time does it take for the bill to fall completely beyond her grasp?

A ball is thrown straight up from the ground. At the very top of its trajectory, what is the direction of its $v$ vector?