Brakes are applied to a car moving with disengaged engine, bringing it to a halt after 2s. What is it's velocity at the moment when the breaks are applied if the coefficient of friction between the road and the tyre is 0.4?
A
3.92ms−1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
7.84ms−1
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
11.2ms−1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
19.6ms−1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is B7.84ms−1 We have: Frictional force =ma μmg=ma=mvt ∴v=μgt =0.4×9.8×2=7.84m/s