States of Equilibrium

Q.

State the condition when a body is in (i) static, (ii) dynamic, equilibrium. Give one example each of static and dynamic equilibrium.

Q.

What is a static?

Q.

In a crystal, the atoms are located at the position of

Q.

A boy of mass $55kg$ runs up a flight of $40$ stairs, each measuring $0.15m$ in $5s$. Column II given numerical value for quantities describe in Column I, match them correctly.

Column 1	Column 2
Force acting on the boy	$550$
Work done by the boy	$3300$
Gain of potential energy by the boy	$33000$
Power developed by the boy	$220$

Q.

An object moving at constant speed is in a state of ____________.

Q.

A gunman, while firing a bullet, should hold the gun tight to his shoulder. Why?

Q.

What are the two types of equilibrium?

Q.

If an unbalanced force acts on a body, the body must accelerate.

1. True
2. False

Q. The escape velocity on the surface of the earth is va- If M and R are the mass and radius of the earth, respectively, then the escape velocity on another planet of mass 2 M and radius R will be

Q. Figure shows a uniform metre rule placed on a fulcrum at its mid-point $O$ and having a weight $40gf$ at the $10cm$ mark and a weight of $20gf$ at the $90cm$ mark. Is the metre rule in equilibrium? If not, how will the rule turn?

1. yes. The rule will not turn
2. yes. The rule will turn anticlockwise
3. No. The rule will turn clockwise
4. No. The rule will turn anticlockwise

Q. Observe the given figure carefully and calculate the net moment about O. Where will the balance tilt? [3 marks]

Q. The value of 5 kgf m in the C.G.S system of units is

1. $9.8\times {10}^7$ dyne cm
2. $4.9\times {10}^7$ dyne cm
3. $9.8\times {10}^8$ dyne cm
4. $4.9\times {10}^8$ dyne cm

Q. A uniform ring of radius R is moving in a horizontal surface with speed V and then climbs upa ramps of inclination 30^° to height H. There is no shipping in entire motion then find the value of H ?

Q. The potential energy of a conservative system is given by $V\left(x\right)=(x^2-3x)$ joule where x is measured in metre. Then its equilibrium position is at

1. 1.5 m
2. 2 m
3. 3 m
4. 1 m
5. 5 m

Q.

DIRECTIONS : Read the following statements and write your answer as true or false.

A body can be in equilibrium under the action of three coplanar forces.

1. True
2. False

Q.

Choose the correct statement:

Statement 1: Unbalanced forces can change the direction of motion.

Statement 2: A balanced force is required to accelerate the motion.

Statement 3: An object moves with a uniform velocity when balanced forces are acting on it and there is no net force acting on it.

Statement 4: Balanced force cannot start a motion.

1. All statements are correct except statement 4.

2. Only statement 1 is correct.

3. Except statement 2, all other statements are correct.

4. Only statement 2 is correct.

Q.

What impulse is equal to?

1. the change in force

2. the change in momentum

3. the change in velocity

4. all the above

Q. What do you understand by equilibrium condition.

Q. When a body remains in the state of rest conditions under the influence of applied forces, the body is in

1. Dynamic equilibrium
2. Static equilibrium
3. Both
4. None

Q. When a body remains in the same state of motion (translational or rotational) under the influence of the applied forces, the body is said to be

1. Both
2. Static equilibrium
3. Dynamic equilibrium
4. None

Q.

For the following block system, if $m_1>>>>m_2$, then

1. the system is in static equilibrium.

2. the system is in dynamic equilibrium.

3. the system is in accelerated equilibrium.

4. the system has net acceleration along the incline.

Q. When the center of gravity of a body lies below the point of suspension or support, the body is said to be in ________ equilibrium. Fill in the blank.

1. Stable
2. Neutral
3. All of the above
4. Unstable

Q. Escape velocity :define

Q. For equilibrium the resultant moment of all the forces acting on the body about the point of rotation should be

1. Greater than one
2. Smaller than one
3. Zero
4. One

Q.

Majorly the equilibrim is classified into _____ types.

1. 3

2. 4

3. 2

4. 5

Q. Dynamic equilibrium is maintained under the influence of

1. Applied forces
2. Friction
3. Gravitation
4. All

Q. A ball is placed in a trough as shown. This can be categorised as equilibrium.

1. unstable
2. stable
3. neutral

Q. Escape velocity

Q.

When a car is in uniform motion along a straight line, then___

1. it is in a static equilibrium

2. it is in an accelerated equilibrium

3. it is in a dynamic equilibrium

4. it is in both static and a dynamic equilibrium

Q. At stable equilibrium position of a body where kinetic energy can`t be zero because it is maximum, Why?