Question

A truck travels 540 Km in 4.5 hours. Find the speed of the truck in Km/hr and in m/sec.
grade 7 cbse

Answer 1

Answer : -

Given that,

Distance = 540 km

Time = 4.5 hours

To find,

The speed of the truck = ?

Before findin' the speed, we've to convert the given values into it's SI unit. As we know, SI unit of length is metre and SI unit of time is second.

So, we have to convert the given values into it's SI unit. Distance will be in metres and time will be in seconds.

As we know,

For distance => 1 km = 1000 m

.°. 540 km = 540,000 metres

For time => 1 hour = 3600

.°. 4.5 hours = 16,200 seconds

We know that,

Speed = $\frac{Distance}{Time}$

Speed = $\frac{540,000\:m}{16,200\:s}$

Speed = $\frac{540,0\cancel{00}}{16,2\cancel{00}}$

Speed = $\frac{5,400}{162}$

Speed = 11.69 m/s (approx)

Now, we have to convert m/s into km/hr to get our answer.

As we know,

1 m/s = 3.6 km/hr

11.69 m/s = 42.084 km/hr.

Therefore, speed in,

(i) Metre / second => 11.69 m/s (approx)

(ii) kilometre / hour => 42.084 km/hr