Question

A car completed 2 rounds of a perfectly circular test track in 1 hour, with a constant speed 88 km/h. Calculate the radius of the track.​

Answer 1

Answer:

r = 14 kM

Explanation:

Distance covered in 2 hrs = Speed × Time

= 88 × 2 = 176 kM

Therefore, 2 × Circumference of circular track = 176 kM

2 × 2πr = 176

4 × 22/7 × r = 176

88/7 × r = 176

r = 176 × 7/88

r = 14 kM

Hope it helps!!

Have a great day!!

Answer 2

Question

A car completed 2 rounds of a perfectly circular test track in 1 hour, with a constant speed 88 km/h. Calculate the radius of the track.

Given

The time taken by the car to complete 2 rounds of the circular track = 1h

speed during this journey = 88 km / h

To Find

Radius of the track 'R'

Formula to be used

Circumference of a circle = 2×π×R

$\sf \large{ speed\frac{distance \: covered}{time \: taken}}$

Solution

since the car took two rounds, it covered a distance twice the length of the Circumference of the circular track.

Distance = 2×2×π×R

$\sf { = 4\times \frac{22}{7} \times r = \frac{88r}{7} km}$

Now, since speed = $\sf \large{ \frac{88r}{r = 7km}}$

Hence,The radius of the track is 7 km.