Question

A motorcycle is moving with speed of 60 km/h. The mass of the motorcycle is 120 kg. Calculate its
kinetic energy
olution
​

Answer 1

Answer:

Note: Mass m = 120 kg

Speed v = 60 km/h

Explanation:

K.E = ½mv²

K.E = ½mv²= (½×120×60) J

= 3600 J

Answer 2

EXPLANATION.

A motorcycle is moving vwith a speed of

=> 60 km/hr = 60 X 5/18 = 50/3 m/s.

=> The mass of the motorcycle = 120 kg.

To calculate the kinetic energy.

$\rm \to \boxed{\green{\: formula \: of \: kinetic \: energy \: = \frac{1}{2} m {v}^{2}} }$

$\rm \to \: \frac{1}{2} \times 120 \times \frac{50}{3} \times \frac{50}{3}$

=> 16666.6 joule.

Deprivation of kinetic energy.

$\rm \to \: \Delta \: k \: = w$

$\rm \to \: \Delta \: k \: = \int \: f(r).dr$

$\rm \to \: \Delta \: k \: = \int \: ma.dr$

$\rm \to \Delta \: k \: = m \int \frac{dv}{dt} . \: dr$

$\rm \to \: \Delta \: k \: = m \int \: \frac{dr}{dt} . \: dv$

$\rm \to \: \Delta \: k \: = m \int \: v \: . \: dv$

$\rm \to \: \Delta \: k \: = \frac{1}{2} mv {}^{2} - \frac{1}{2}m v_{0} {}^{2}$

$\boxed{\green{\rm \to \: ke \: = \: \frac{1}{2}m {v}^{2} }}$