wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A car starts from rest. It has to cover a distance of 500 m and come to rest at the end of the journey. The coefficient of friction between the road and the tyre is 12. The minimum time in which the car can cover this distance is (g=10 m/s2)

A
20 seconds
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
10 seconds
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
30 seconds
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
15 seconds
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 20 seconds
Maximum acceleration and maximum retardation of the car can be
μg or 12×10=5 m/s2
The corresponding velocity-time graph is as shown in the figure.
Let t0 be the time of acceleration and retardation. Then
vm=μgt0=5t0
Now, displacement = area under vt graph
500=12×2t0×5t0
or t0=10 seconds
Total time of journey is 2t0 or 20 seconds.
Hence, the correct answer is option (a).

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Warming Up: Playing with Friction
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon