Question

An engine in an automobile can develop a power of $4HP.$If the force developed by the engine is $250N,$Find the uniform velocity at which the automobile is moving. Take $\left[1HP=750W\right]$.

Answer 1

Step 1: Given data

Power of engine $\left(P\right)=4HP$

Force developed by the $\left(F\right)=250N$

Velocity $\left(v\right)=?$

Conversion of HP into watts

$$\begin{gathered} As,1HP=750W \\ 4HP=4\times 750W=30,00W \end{gathered}$$

Step 2: Formula used

According to the formula of power

$$\begin{gathered} Power=Force\times velocity \\ P=F\times v \\ v=\frac{P}{F}...........\left(a\right) \end{gathered}$$

Step 3: Calculating the velocity

On, putting all the given values in equation (a), we get

$v=\frac{30,00W}{250N}=12m{s}^{-1}$

Hence, the velocity of the engine will be $v=12m{s}^{-1}$.