Question

A car travelling on a straight road initially at 54 km/h accelerates for 2.3 s at a constantacceleration of 8.2 m/s2. What is the car's final speed, in m/s?(Hint: You must first convert 54 km/h to m/s.)

Answer 1

Given:

The initial speed of the car is,

`u=54\text{ km/h}`

The acceleration is,

`a=8.2\text{ m/s}^2`

The time for which the car is travelling with acceleration is,

`t=2.3\text{ s}`

To find:

The car's final speed

Step-by-step explanation:

The initial speed of the car is,

`\begin{gathered} u=54\text{ km/h} \\ =(54*1000)/(3600)\text{ m/s} \\ =15\text{ m/s} \end{gathered}`

The final speed of the car is,

`v=u+at`

Substituting the values we get,

`\begin{gathered} v=15+8.2*2.3 \\ =33.9\text{ m/s} \end{gathered}`

Hence, the final speed is 33.9 m/s.