Question

During a free fall Swati was accelerating at -9.8m/s^2. After 120 seconds how far did she travel? Use the formula =1/2 * t^2 to solve your answer. (Do not forget to keep units in your answer.)

Answer 1

Answer: 70.56 km

From the Equation of motion:

$s=ut+\frac{1}{2}at^2$

where, $s$ is the distance covered, $u$ is the initial speed, $a$ is the acceleration and $t$ is the time.

In the question it is given that the Swati was in a free fall. This means that her initial velocity is 0 and she is just falling due to gravity. It means she is experiencing acceleration due to gravity. $a=g=-9.8 m/s^2$ for time $t=120 s$

Substitute the values in the equation of motion:

$s=0-\frac {1}{2}9.8ms^{-2}\times (120s)^2=\frac{-141120}{2}m=70560 m=70.56 km$ (ignore the negative sign)