A body is released from rest (or dropped) under gravity, and the question asks for time, distance, velocity, or position at a specific point during the fall.
156. A particle starts from rest at the origin on the $x$-axis with constant acceleration, and at moment $t = 5\text{s}$ reaches position $x = -122.5\,\text{m}$. How many meters per second does the speed of the particle reach at this moment? (1) $19.6$ (2) $33.4$ (3) $45.0$ (4) $49.0$
A ball is released from the top of a tower of height $h$ metres. It takes $T$ seconds to reach the ground. What is the position of the ball in $\mathrm { T } / 3$ seconds? (1) $\mathrm { h } / 9$ metres from the ground (2) $7 \mathrm {~h} / 9$ metres from the ground (3) $8 \mathrm {~h} / 9$ metres from the ground (4) $17 \mathrm {~h} / 18$ metres from the ground.
A ball is dropped from the top of a 100 m high tower on a planet. In the last $\frac{1}{2}\,\mathrm{s}$ before hitting the ground, it covers a distance of 19 m. Acceleration due to gravity (in $\mathrm{m\,s^{-2}}$) near the surface on that planet is $\underline{\hspace{1cm}}$