Question

An impala is an African antelope capable of a remarkable vertical leap. In one recorded leap, a 45 kg impala went into a deep crouch, pushed straight up for 0.21 s, and reached a height of 2.5 m above the ground.

Part A

To achieve this vertical leap, with what force did the impala push down on the ground?

PartB

What is the ratio of this force to the antelope's weight?

Answer 1

Impulse vector = F?????t = ?mv? = m?v?

[the deer pushes the ground with an average force F??? for time = ?t s and then gains a vertical velocity v from rest as the ground exerts the same force on the deer upwards as per Newton's III law ]

the deer's velocity in time ?t changes from 0 to v

F???(0.21) = ?mv? = m?v = 45[v - 0] = 45v --------------------> (i)

also from Energy Conservation => the kinetic energy of the deer is changed to potential energy at the highest point of the leap.

=> k.e =