A ball is dropped on a floor and bounces back to a height somewhat less than the original height, which of the curves depicts its motion correctly?

Question

A ball is dropped on a floor and bounces back to a height somewhat less than the original height, which of the curves depicts its motion correctly? (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

When a ball is dropped on a floor, then

y = \frac{1}{2} g t^{2}

\dots (i)

So, the graph between

y

and

t

is a parabola. Here

y

decreases as time increases. When the ball is bounces back then

y = u t - \frac{1}{2} g t^{2}

\dots (ii)

Eq. (ii) is also the form of a general equation of parabola So, the graph between

y

and

t

will be a parabola. Here,

y

increases when time increases. Hence, the required graph between

y

and

t

is shown in the figure

Q. A ball is dropped on a floor and bounces back to a height somewhat less than the original height, which of the curves depicts its motion correctly?