Mechanical Advantage

Q.

What is the pitch of a screw gauge?

Q.

Explain the following:

It is easier to turn the steering wheel of a large diameter than that of a small diameter.

Q.

A man can open a nut by applying a force of 150 N by using a lever handle of length 0.4 m. What should be the length of the handle. If he is able to open it by applying a force of 60 N?

Q.

Give four examples of couple in everyday life.

Q.

The SI unit of work is Joule. It is expressed in the terms of mass, length and time as

1. $kg{m}^2{s}^{-3}$

2. $kg{m}^3{s}^{-2}$

3. $k{g}^2{m}^2{s}^{-2}$

4. $kg{m}^2{s}^{-2}$

Q.

What is pitch of Vernier Calipers?

Q.

calculate the length of the arm of the couple if a force of 13N produces a moment of a couple of14.3 N-m

Q.

A ball is in free fall. Upwards is taken to be the positive direction. The vertical component of the displacement of the ball during a short time interval is _____ during ascent, and ___________ during descent.

Q.

A sheet of paper falls faster when it is crumpled because the crumpled sheet of paper

1. experiences a stronger force of gravity

2. experiences a greater acceleration due to gravity

3. experiences less air resistance

4. has more weight

Q.

Define the following: Rigid body

Q. What are ball bearings?

Q.

Differentiate between the buoyant force and weight of the body.

Q.

A mechanic can open a nut by applying 120 N force using a lever of 50 cm length. How long should the handle be, if he wishes to open, it by applying a force of only 40 N?

1. 1 m

2. 2 m

3. 1.5 m

4. 2.5 m

Q.

State three functions of a machine?

Q.

Give any two effects of a force on a rigid body?

Q.

The point of action of force on a rigid body is:

1. Fixed point on rigid body

2. Fixed point but can be transferred anywhere along the line of action of force.

3. Fixed point but can be transferred anywhere along the direction of force.

4. Fixed point but can be transferred anywhere opposite to the direction of force.

Q.

Define Lever what are its kinds?

Q.

Why is the handle of an ordinary water handpump made longer?

1. The mechanical advantage decreases with the increase in effort arm.

2. No change in mechanical advantage.

3. The mechanical advantage increases with the increase in effort arm.

4. It will increase the efficiency.

Q.

A Couple of 15 N force act on a rigid body, such that the arm of the couple is 85 cm calculate the moment of couple in SI system.

Q.

A stone is gently dropped from a height of 80 m. If its velocity increases uniformly at the rate of 10 ms^-2, with what velocity will it strike the ground?

Q.

An actual pulley system always has a mechanical advantage less than a velocity ratio. It is because:

1. a part of effort is wasted in overcoming friction

2. a part of the effort is wasted in overcoming the load of movable block

3. both (a) and (b)

4. none of the above

Q. A _____________ exerted by an object on another is a force.

1. pressure
2. magnitude
3. contact or non-contact
4. push or pull

Q.

What is meant by the term inertia?

Q.

Force in linear motion has its analog in rational motion?

1. Moment of inertia

2. Torque

3. Angular momentum

4. Weight

Q.

If mechanical advantage of a machine is less than 1 , it is used to gain _____

Q.

Consider an imaginary planet whose mass is 8 times that of the earth and whose radius is 2 times that of the earth. What is the value of acceleration due to gravity on the surface of that planet? If a man of mass of 60 kg stands on the surface of that planet, What will be his weight? Given that the acceleration due to gravity on the surface of the earth is 9.8 ms^-2.

Q.

A crowbar of length $2.5m$ is pivoted at a point $25cm$ from its tip. Calculate mechanical advantage of crowbar.

Q.

An effort of 50kgf is applied at the end of a lever of the second order, which supports a load of 750kgf, such that the load is at a distance of 0.1m from the hinge. find the length of the lever.

Q. Moving parts of most machines use ball bearings to reduce friction.

1. True
2. False

Q.

State the units of moment of couple in

(i) CGS system

(ii) S I system