Share
The lightweight wheel on a road bike has a moment of inertia of 0.097 kg⋅m2. A mechanic, checking the alignment of the wheel, gives it a qui
Question
The lightweight wheel on a road bike has a moment of inertia of 0.097 kg⋅m2. A mechanic, checking the alignment of the wheel, gives it a quick spin; it completes 5 rotations in 2.4 s. To bring the wheel to rest, the mechanic gently applies the disk brakes, which squeeze pads against a metal disk connected to the wheel. The pads touch the disk 7.1 cm from the axle, and the wheel slows down and stops in 1.4 s.
What is the magnitude of the friction force on the disk?
in progress
0
Physics
4 years
2021-08-18T19:46:14+00:00
2021-08-18T19:46:14+00:00 2 Answers
6 views
0
Answers ( )
Answer:
Explanation:
Given:
moment of inertia of the wheel,
no. of rotation of the wheel,
time taken to complete the above said rotations,
distance of application of force by the brake pads,
time taken to stop,
Now the angular velocity of the wheel:
According the Newton’s second law of motion:
Answer:
The magnitude of the friction force on the disk is 12.76 N.
Explanation:
Given that,
Moment of inertia = 0.097 kg m²
Number of rotation = 5
Time = 2.4 s
Distance = 7.1 cm
Time = 1.4 s
We need to calculate the angular velocity
Using formula of angular velocity
Put the value into the formula
We need to calculate the magnitude of the friction force on the disk
Using formula of torque
Put the value into the formula
Hence, The magnitude of the friction force on the disk is 12.76 N.