Question

A truck of mass 1200kg changes its speed from 54km/h to 72km/h.
Find the increase in its kinetic energy.

Answer 1

Howdy!!

your answer is ----

Given , mass of truck = 1200kg
& S
v1 = 54km/h or 15m/s and
v2 = 72km/h or 20m/s

therefore , change in kinetic energy is
$\frac{1}{2} m {v2}^{2} - \frac{1}{2} m {v1}^{2} \\ = \frac{1}{2} \times 1200 \times 175 \\ = 105000joule$

hence, 105000 joule energy increase

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hope it help you

Answer 2

Given , mass of truck = 1200kg
& S
v1 = 54km/h or 15m/s and 
v2 = 72km/h or 20m/s
change in kinetic energy is equal to
$\frac{1}{2} \: m {v}^{2} - \frac{1}{2} m {v} {1}^{2} \\ \frac{1}{2} \times 1200 \times 175 \\ = 105000 \: joules \\ hope \: it \: helps \: you$