Question

a car moves with a uniform velocity of 72 km h-1 for 15 second on a national highway over a straight stretch of road . calculated the distance travelled

Answer 1

First get your units standardised, so: 1h = 60 minutes of 60s each so 60x60=3600s. 72km/h or 72000m/3600s = 20m/s. When the car slows it starts at 20m/s and finishes a 0m/s so the average speed over the 100m is 10m/s and if you’re travelling 10m each second, 100m will take 10s.

Answer 2

Given Information:

A car moves with a uniform velocity of 72 km/h⁻¹ for 15 second on a national highway over a straight stretch of road . Calculate the distance travelled.

Solution:

We have,

• Speed = 72km/h
• Time = 10s
• Distance = ?

At first we have to convert the speed 72km/h into m/s.

To convert km/h into m/s, we have to multiply the given speed by 5/18.

So, 72 × 5/18

= 360/18

= 20m/s

Now, we know that,

• Speed = Distance/Time
• Distance = Speed × Time
• Distance = 20 × 15
• Distance = 300m

Therefore, distance travelled by a car is 300m