Question

A person on a bike (m=90 kg) is traveling 4 m/s at the top of a 2 m hill. what is the bikers total energy?

Answer 1

Answer:

720 J

Explanation:

Kinetic Energy = 1/2 * m *(v*v)

M= 90 kg

V=4 m/s

KE=1/2 * 90 * (4*4)

KE= 45*16= 720 J

Answer 2

$\frac{m}{s}$Answer: D) 720 J

Explanation:

Given : m=90kg

Total Energy = K. E. + P. E.  =$\frac{1}{2}$$mv^{2}$+mgh

Since bike is present over a surface of Earth (top of hill) hence h=0m.

Therefore,

Total Energy=  $\frac{1}{2}$*90kg*$(4m/s)^{2}$+(90kg)*(9.81$\frac{m}{s}^2$)x(0)

= 720 J

Hence total energy of bike is equal to 720 J