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1. What is the moment of inertia of a solid sphere with 10 kg mass and 4 meter r

ID: 2035072 • Letter: 1

Question

1. What is the moment of inertia of a solid sphere with 10 kg mass and 4 meter radius? A. 160 kg m2 B. 80 kg m2 C. 64 kg m2 D. 40 kg m2 2. If a sphere rolls without slipping down an incline and a box slides down without friction on the incline from the same height, which will reach the bottom first? A. the sphere B. the box C. same 3. A wheel rotates 360 degree clockwise under the torque of 15 N m in the clockwise direction, what is the work done by that torque? A. 24 ] B. 15 J C. 94.2 J D. 1800J 4. What is the angular momentum of a hoop with 5 kg mass and 4 m radius rotating around its axis at 3 rad/s? A. 80 kg m2/s . 240 kg m2/s C. 120 kg m2/s D. 720 kg m2/s 5. Which of the following is the requirement for an object to remain at rest (static equilibrium)? A. The net force acting on it must be zero. B. The net torque applied to it must be zero. C. Both A and B D. Linear acceleration is zero.

Explanation / Answer

1)

Isoli-sphere = 2/5 * m* r2

= (2/5) *10*42

= 64 kg-m2 (option c)

2)

(A) sphere

3)

W = torque x angular displacement

= 15 * 2pi [since 360 degrees is 2pi]

= 94.2 J (optionc)

4)

Ihoop = mr2 = 5*42 = 80 kg-m2

We know, L = Iw

=> 80*3 = 240 kg-m2/s (option B)

5) Option (c)