Question

A body moving with uniform acceleration, has initial velocity 45 km/hr; and acceleration 20 cm/s square. Find its velocity after 25 seconds.

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{u}=45\mathrm{km}/\mathrm{h} \\ \mathrm{u}=45\times \frac{5}{18}\mathrm{m}/\mathrm{s} \\ \mathrm{u}=\frac{25}{2}\mathrm{m}/\mathrm{s}=12.5\mathrm{m}/\mathrm{s} \\ \mathrm{a}=20\mathrm{cm}/\mathrm{s}=0.2\mathrm{m}/\mathrm{s} \\ \mathrm{t}=25\mathrm{s} \\ \mathrm{v}=\mathrm{u}+\mathrm{at} \\ \mathrm{v}=12.5+0.2\times 25 \\ \mathrm{v}=12.5+5=17.5\mathrm{m}/\mathrm{s} \end{gathered}$$