Answer:
The Skater's final angular speed =8rad/s
Explanation:
Let initial momentum of inertia be I1
Let final momentum of inertia be I2
But I2= I1/2
It is decreased by one-half
There is no external torque on the system, therefore
I1w1=I2w2
I1×4=(I1/2)×w2
Dividing through by I1 on both sides leaves you with:
4=w2/2
Cross multiply
W2=4×2=8rad/s
It means you need to put a lot of heat into it to raise its temperature by just one degree.
Answer:
B
Explanation:
Gravity always pulls down.
Answer:
The no of revolutions is 2.032 revolution.
Explanation:
Given that,
Moment of inertia = 0.85 Kgm²
Radius = 170 mm
Force = 32 N
Time = 2s
We need to calculate the angular acceleration
Using formula of torque
Where, F = force
r = radius
I = moment of inertia
Put the value into the formula
We need to calculate the rotational speed
Using equation of angular motion
We need to calculate the angular position
Using equation of angular motion
We need to calculate no of revolutions
Hence, The no of revolutions is 2.032 revolution.