Speed & Acceleration

Question

Falling objects drop with an average acceleration of 9.8 m/s/s. if an object falls from a tall building, how long will it take before it reaches a speed of 49 m/s

Answer 1

The equation that describes the change in velocity (acceleration) of a falling object is:

V_f = V_i + a*t

where:

V_f = final velocity

V_i = initial velocity

a = acceleration

t = time

In the given example, at t=0s, the velocity (V_i ) is 0 m/s, as the object is falling from rest.

The acceleration is given to be 9.8m/s². The final velocity (V_f ) is 49m/s. Our only unknown is the amount of time, t.

Plugging these values into the above equation gives us:

49m/s= 0m/s + 9.8m/s² * (t)

Solving for t:

t= (49m/s) / (9.8m/s²)

t= 5 seconds

It takes the falling object 5 seconds to reach 49m/s.