Question

a motorcycle is trying to leap across the canyon by driving horizontally off a cliff 38 m/s. Ignoring air resistance, find the speed with which the cycle strikes the ground on the other side

Answer 1

46.15m/s

Step-by-step explanation:

We are given that

Initial speed,u=38 m/s

Height of cliff,h=70 m

We have to find the speed with which the cycle strikes the ground at a height 35 m on the other side.

h'=35 m

Using conservation law of energy

`(1)/(2)mu^2+mgh=(1)/(2)mv^2+mgh'`

`(1)/(2)u^2+gh=(1)/(2)v^2+gh'`

Where
`g=9.8m/s^2`

Substitute the values

`(1)/(2)(38)^2+9.8* 70=(1)/(2)v^2+9.8* 35`

`(1)/(2)v^2=(1)/(2)(38)^2+9.8* 70-9.8* 35=1065`

`v=√(2* 1065)`

`v=46.15m/s`