Inertia

Q.

Why are the wheels of vehicles provided with mud guards?

Q. A block of weight $10\text{N}$ is placed on a horizontal table. A person pushes the block from the top by exerting a downward force of $5\text{N}$ on it. Find the force exerted by the table on the block in equilibrium.

1. $25\text{N}$
2. $10\text{N}$
3. $15\text{N}$
4. $20\text{N}$

Q. 1. A stone is dropped from a balloon at an altitude of 300m. how long will the stone take to reach the ground if(a) the balloon is ascending with a velocity of 5m/s (b) the balloon id descending with a velocity of 5m/s (c) the balloon is stationary?

Q.

The ratio of the inertial mass to gravitational mass is equal to

A.1/2

B.1

C.2

D. No fixed

Q.

Moment of Inertia of a thin uniform rod rotating about the perpendicular axis passing through its centre is I. If the same rod is bent into a ring and its moment of inertia about its diameter is I’, then the ratio $\frac{I}{I^{\prime }}$ is

1. $\frac{2}{3}{\pi }^2$

2. $\frac{3}{2}{\pi }^2$

3. $\frac{5}{3}{\pi }^2$

4. $\frac{8}{3}{\pi }^2$

Q.

A water tanker filled up to $\frac{2}{3}$ of its height is moving with a uniform speed. On sudden application of the brake, the water in the tank would?

1. move backward

2. move forward

3. be unaffected

4. rise upwards

Q.

What happens to the passengers in a moving bus when bus takes right turn?

Q.

A truck and a car are moving with the same kinetic energy on a straight road. Their engines are simultaneously switched off. Which one will stop at a lesser distance?

Q.

Why we tend to fall forward when a car stops suddenly?

Q. What is the difference between inertial mass and gravitational mass? How gravitational mass related to Einstein's general theory of relativity

Q.

When a carpet is beaten with a stick, dust comes out of it. Explain.

Q. Which of the following statements is true about uniform circular motion?

1. Acceleration does not exist.

2. Acceleration exists but is constant.

3. Acceleration exists but its magnitude is constant and only direction changes.

4. Acceleration exists and both magnitude and direction changes.

Q. A man getting down a running bus falls forward because

1. Due to inertia of rest, road is left behind, and man reaches forward
2. Due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road
3. He leans forward as a matter of habit
4. Of the combined effect of all the three factors stated in (a). (b) and (c).

Q.

An object is placed far away from all the objects that can exert force on it. A frame of reference is constructed by taking the origin and axes is fixed in this object. Will the frame be necessarily inertial?

Q. A block of mass $m$ is pulled slowly by a minimum constant force on a horizontal surface through a distance $x$. The coefficient of kinetic friction is $\mu$. Find the work done by force $F$.

Diagram

1. $\frac{2l}{\sqrt{V^2-v^2}}$
2. $\frac{2vl}{V^2-v^2}$
3. $\frac{\mu \text{mgx}}{1+{\mu }^2}$
4. $\frac{2Vl}{V^2-v^2}$

Q.

When a train starts, the head of a standing passenger seems to be pushed backward. Analyze the situation from the ground frame. Does it really go backward?

1. Yes

2. No

Q. Forces $F_1\text{and}{F}_2$ act on a point mass in two mutually perpendicular directions. The resultant force on the point mass will be

1. $F_1-F_2$
2. $F_1+F_2$
3. $\sqrt{F_1^2+F_2^2}$
4. $F_1^2+F_2^2$

Q.

A rider on a horse falls back when the horse starts running, all of a sudden because

1. the rider is taken back

2. the rider is suddenly afraid of falling

3. the inertia of rest keeps the upper part of the body at rest while the lower part of the body moves forward with the horse

4. none of the above

Q. Inertia is that property of a body by virtue of which the body is

1. unable to change by itself the state of rest
2. unable to change by itself the state of uniform motion
3. unable to change by itself the state of rest and of uniform linear motion
4. unable to change by itself the direction of motion

Q. Find the radius of gyration of a thin uniform rod of mass $M$ and length $L=3\text{m}$ about an axis passing through one end and perpendicular to rod as shown in figure.

1. $3m$
2. $\sqrt{3}m$
3. $\frac{1}{\sqrt{3}}m$
4. $1m$

Q.

When a running car stops suddenly, the passengers are jerked_________.

Q.

Place a waterfilled tumbler on a tray. Hold the tray and turn around as fast as you can. We observe that the water spills. Why?

Q.

The inertia of _________ is responsible for the rider falling in the forward direction when his horse stops suddenly.

Q.

We get a sudden jerk backward if the bus starts suddenly.

Q.

Why do athletes run for a while before taking a long jump?

Q. When three forces of $50N,30N$ and $15N$ act on a body, then the body is

1. At rest
2. Moving with a uniform
3. Moving with an acceleration
4. In equlibrium

Q. Distinguish between Inertia of motion and inertia of direction

Q. A block is kept on a frictionless inclined surface with angle of inclination $\alpha$. The incline is given an acceleration
$\alpha$ to keep the block stationary. Then $\alpha$ is equal to

1. $\frac{g}{\tan \alpha }$
2. $g\tan \alpha$
3. $g$
4. $g\text{cosec}\alpha$

Q. Inertia is that property of a body by virtue of which the body is :

1. Unable to change by itself the state of rest.
2. Unable to change by itself the state of uniform motion.
3. Unable to change by itself the state of rest or of uniform motion.
4. Unable to change by itself the direction of motion.

Q.

A body moves from A to B in 3 sec. What is its average velocity w.r.t. the origin?

1. 35 m/s

2. -10 m/s

3. 10 m/s

4. -35 m/s