Question

A car is moving with a uniform speed of 15.0 m/s along a straight path. What is the distance covered by the car in 12.0 minutes?1) 1.02 × 10–3 km2) 1.80 × 10–1 km3) 8.00 × 10–5 km4) 1.08 × 101 km

Answer 1

Given,

The speed of the car, s=15.0 m/s

The time interval, t=12 mins

1 min=60 s

Thus 12 mins are

$\begin{gathered} 12\text{ min}=\frac{12\text{ min}\times60\text{ s}}{1\text{ min}} \\ =720\text{ s} \end{gathered}$

Thus t=720 s

The speed is given by the ratio of the distance covered to the time interval. That is,

$s=\frac{d}{t}$

Where d is the distance covered by the car in the given time.

On rearranging the above equation,

$d=st$

On substituting the known values,

$\begin{gathered} d=15.0\times720 \\ =10800\text{ m} \\ =10.8\text{ km} \\ =1.08\times10\text{ km} \\ =1.08\times10^1\text{ km} \end{gathered}$

Therefore the distance covered by the car in the given time is 1.08×10¹ km

Thus the correct answer is option 4.