Introduction

Q.

1 newton = __ dyne.

1. ${10}^{5}dyne$.

2. ${10}^{7}dyne$.

3. ${10}^{2}dyne$.

4. ${10}^{3}dyne$.

Q.

1 gram force equals___dyne.

(acceleration due to gravity $g=9.8\frac{m}{s^2}$)

Q.

What is a balanced force?

Q.

What is the source of centripetal force, when an electron revolves around the nucleus?

Q.

State and explain the law of inertia.

Q.

When a horse pulls a wagon, the force that causes the horse to move forward is the force.

1. The horse exerts on the wagon

2. The horse exerts on the ground

3. The wagon exerts on the horse

4. The ground exerts on the horse

Q. Which law is also known as the law of inertia?

1. Newton’s first law of motion
2. Newton’s second law of motion
3. Newton’s third law of motion
4. Law of conservation of momentum

Q.

A force produces an acceleration of $5.0cm/s^2$ when it acts on a body of mass 20 g. The force in newton is:

1. $2\times {10}^{-3}N$
   

2. $4\times {10}^{-3}N$
   

3. $1.0\times {10}^{-3}N$
   

4. $5\times {10}^{-3}N$

Q.

A force can :

1. All of the above

2. Change the direction of motion

3. Change the speed of the motion

4. Break a rigid body

Q.

Can unbalanced force can cause a change in shape and size of objects?

Q. Planetary orbits are in shape.

1. perfect circular
2. elliptical
3. parabolic
4. semi-circular

Q.

A body moves in a vertical semicircle of radius r from the lowest point to highest point. What is the amount of work done? (Assume mass of the body to be 'm' kg and acceleration due to gravity to be $gm{s}^{-2}$)

1. 2mgr

2. mgr

3. mgr

4. 2mgr

Q. Specific heat of water is 4.2 J/g^°C. If light of frequency 3 109Hz is used to heat 400 gm of water from 20^°C to 40^°C, the number of photons needed will be

Q. During ancient times, people believed that the Earth was the centre of the universe and all celestial bodies including the Sun revolved around the Earth. If this hypothesis were to be true, then

1. Earth's mass should be proportionally much higher than the mass of Sun
2. Mass of Earth and Sun should be comparable
3. The sum of masses of all celestial bodies should be comparable to that of the Earth
4. Sun's mass should be proportionally much higher than the mass of Earth

Q. Question 1 (c)
Which of the following has more inertia:
(c) a five-rupee coin and a one-rupee coin?

Q.

Acceleration due to gravity $g=9.8\frac{m}{s^2}$. Which of the following is/are correct?

1. 1 kgf = 9.8 newton

2. 1 kgf = 980 newton

3. 1 gf = 9.8 dyne

4. 1 gf = 980 dyne

Q.

Choose the correct answer regarding force.

1. Force can be heard by humans

2. Force can be seen by humans

3. Humans can feel the effect of force

4. All of the above

Q. An electrolytic cell converts electrical energy into _____ energy.

1. chemical
2. mechanical
3. sound
4. light

Q. An external force applied on a body cannot:

1. change its direction.
2. change its speed.
3. change its shape.
4. change its mass.

Q.

What precautions must be observed before measuring the mass with the electronic balance?

Q.

If a force of 200 newtons is required to move a wagon up a frictionless hill at constant speed, the force needed to left the wagon roll downhill at constant speed is________.

Q.

Give reasons:

A)When a bus takes a U-turn, passengers sitting inside are thrown a side.

B)It is easier to stop a tennis ball than a cricket ball moving with the samespeed.

C)A passenger jumping out of a rapidly moving bus falls forward with his face downwards.

D)A person sitting in bus falls forward when moving bus suddenly stops and people sitting in bus fall backward when bus suddenly starts.

Q. Define Inertia. Describe a simple experiment to demonstrate the inertia of rest.

Q. Suppose, you and your friend are pulling on either end of a rope in opposite directions. According to Newton's Third Law, what is the reaction to the force of your hand that is being applied on the rope?

1. The force of friction between the ground and your shoes
2. The force of the rope pulling on your hand in the opposite direction
3. The force of the rope pulling your friend's hand
4. The force of your friend pulling on the rope in the opposite direction

Q.

A fielder drags his hands towards him gradually along with the moving ball while taking a catch. What is the reason of this?

1. It reduces the impact of catching the fast moving ball.

2. It reduces the frictional forces between hand and the ball

3. It increases the momentum of the ball.

4. It increases the accelaration of the ball

Q. Derive the relationship between a newton and a dyne.

Q. S IS REPRESENT AS DISTANCE OR DISPLACEMENT ? IF IT IS DISTANCE THEN DISPLACEMENT IS REPRESENT AS_________. IF IT IS DISPLACEMENT THEN DISTANCE IS REPRESENT AS_________.

Q. What is the number of seconds in a solar day?

1. oranges

2. King's feet

3. Hand's span

4. None of these

Q. Law of inertia is another name for _________ .

1. Newton’s first law of motion
2. Newton’s second law of motion
3. Newton’s third law of motion
4. None of the above

Q. Question 1 (a)
The following is the distance-time table of an object in motion:
$\begin{array}{cc}Timeinseconds& Distanceinmetres\\ 0& 0\\ 1& 1\\ 2& 8\\ 3& 27\\ 4& 64\\ 5& 125\\ 6& 216\\ 7& 343\end{array}$
(a) What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?