Question

1. The dimensional formula for force is
i) MLT-1, ii) MLT-2, iii) MLT-3, iv) M0LT-2
2. The dimension of work is
i) MLT-2, ii) M1L2T2, iii) M1L2T-2, iv) ML2T-1
3. What do you mean by the unit of a physical quantity? Write down the fundamental units in Sl with their symbols.
4. The momentum is equal to
i) mass x velocity, ii) force x acceleration, iii) force x time, iv) force x distance
5. State Newton's second law of motion and hence find a relation between force and its effect.
6. Define momentum and impulse. Show that impulse is equal to the change in momentum.
7. What is force? What are its absolute and gravitational units? How are these related to each other?
8. A bullet of mass m is fired from a gun of mass M with a horizontal velocity v. Calculate the recoil velocity V of the gun.
9. Define circular motion and angular velocity.
10. Define centripetal force and derive the relation tan=2 (where the symbols have their usual meanings).
11. Define centripetal force. Does it do any work?
12. Why centrifugal force is called a pseudo force?
13. Why is it easier to roll a gas cylinder than to pull it along the road?
14. Find the distance travelled by a body before coming to rest if it is moving with a speed of 10 m/s and the coefficient of friction between the body and the ground is 0.4.
15. Define work, power and energy and write their SI units.
16. Show that the kinetic energy of a body of mass ‘m’ moving with velocity ‘v’ is 122.
17. What is meant by positive work, negative work and zero work? Give one example of each.
18. Show that the total energy of a freely falling body is constant.
19. State work-energy principle.
20. Find the expression of kinetic energy of a body of mass m moving with velocity v.
21. A body of mass 5 kg moving at a speed of 20 m/s accelerates at 3 m/s2 for 5 seconds. Find its final kinetic energy.
22. A lift is designed to carry a load of 4,000 kg through 10floors of a building averaging 6 metre per floor in 10 s. Calculate the horse power of the lift.
23. Two masses, one n times as heavy as the other, have equal kinetic energy. What is the ratio of their momenta?
24. a) Which force is necessary for rotation of a body in a circular path with uniform angular velocity? Write its expression and explain the symbols used.
b) What is the rotational analog of mass?
c) Define angular momentum. What is its relation with torque?
25. State & explain the principle of conservation of angular momentum. Give example.
26. Define moment of inertia of a rigid body about a given axis. Write its unit. Is the moment of inertia a scalar quantity?
27. What do you mean by radius of gyration?
28. What is parallel axis theorem and perpendicular axis theorem?​

Answer 1

Answer:

Science, any system of knowledge that is concerned with the physical world and its phenomena and that entails unbiased observations and systematic experimentation. In general, a science involves a pursuit of knowledge covering general truths or the operations of fundamental laws.

Answer 2

The SI has special names for 22 of these derived units (for example, hertz, the SI unit of measurement of frequency), but the rest merely reflect their derivation: for example, the square metre (m2), the SI derived unit of area; and the kilogram per cubic metre (kg/m3 or kg⋅m−3), the SI derived unit of density.