Question:
Do action and reaction act on the same body?
Answer:
No, action and reaction act on different bodies.
Force and Laws of Motion
Q 1.
While driving on a highway, an insect strikes on the car windshield and splatters. Which experiences greater impact (force): an insect or the windshield?
Q 2.
On what factor does inertia of a body depend ?
Q 3.
Do action-reaction forces produce the same magnitude of acceleration ?
Q 4.
Fill in the blanks :
The study of motion of a body under the action of a force is called ______.
Q 5.
Are action-reaction forces simultaneous ?
Q 6.
Using second law of motion, derive the relation between force and acceleration.
Q 7.
What is the unit of force in c.g.s system?
Q 8.
Can balanced forces change the shape and size of an object?
Q 9.
In the above question, which body is damaged more ?
Q 10.
Explain why a player lowers his hands while catching a cricket ball.
Q 11.
A TV set is lying on a table. The TV set experiences a gravitational force (pull) downwards (FW) by the Earth. It also experiences a force on it due to table in contact i.e. (FTable-TV) in upward direction. Do these forces form an action-reaction pair? Do these forces follow Newton's third Law of motion?
Q 12.
Can every force produce motion in every object?
Q 13.
Can balanced forces change the shape and size of a body ?
Q 14.
The masses of two objects are 2 kg and 20 kg. Which has greater inertia ?
Q 15.
A car weighs 1500 kg.Its speed time graph is shown in Fig. Calculate the force required at the end of 5 seconds to bring the car to a stop within one second.
Q 16.
When a branch of a tree is shaken, some of the fruits may fall down.Why ?
Q 17.
It is difficult to balance our body when we accidentally slip on a peel of banana. Explain why?
Q 18.
What is the total momentum of a bullet and a gun before firing?
Q 19.
What acceleration is produced by a force of 5 N acting on a body of mass 20 kg ?
Q 20.
An object experiences a net zero external unbalanced force.Is it possible for the object to be travelling with a non-zero velocity ? If yes,state the conditions that must be placed on the magnitude and direction of the velocity.If no,provide a reason.
Q 21.
A body of mass 25 kg has momentum of 125 kg m/s. What is the velocity of the body?
Q 22.
A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. Find its acceleration. Find the force acting on it if its mass is 7 metric tonnes. (Hint: 1 metric tonne = 1000 kg.)
Q 23.
Two persons manage to push a motorcar of mass 1200 kg at a uniform velocity along a level road. The same motorcar can be pushed by three persons to produce an acceleration of 0.2m s-2. With what force does each person push the motorcar?
(Assume that all persons push the motorcar with the same muscular effort.)
Q 24.
Fill in the blanks :
Newton's second law of motion states that the rate of change of ______ of a body is directly proportional to the force and takes place in the same direction as the ______.
Q 25.
What are unbalanced forces?
Q 26.
Define 1 Newton force.
Q 27.
What is the SI unit of impulse.
Q 28.
Why mass is sometimes called coefficient of linear inertia?
Q 29.
A feather of mass 10 g is dropped from a height.It is found to fall down with a constant velocity.What is the net force acting on it ?
Q 30.
What is the total momentum of the bullet and the gun on firing ?
Q 31.
In the above question,which body undergoes greater change in momentum ?
Q 32.
Name the various effects of force.
Q 33.
Explain what is meant by momentum of a body.Is it a scalar or a vector ? What are its units ?
Q 34.
State Newton’s first law of motion. Hence define force and inertia.
Q 35.
Fill in the blanks :
An umbrella protects us from rain it is based on the property of _____________.
Q 36.
Fill in the blanks :
On what factor does the inertia of a body depends? ____________
Q 37.
Which law of motion gives the measure of force?
Q 38.
Name the principle on which a rocket works.
Q 39.
A motorcar is moving with a velocity of 108 km/h and it takes 4 second to stop after the brakes are applied.Calculate the force exerted by the brakes on the motorcar if its mass alongwith the passengers is 1000 kg.
Q 40.
A force of 4 N acts on a body of mass 2 kg for 4 s.Assuming the body to be initially at rest,find (a) its velocity when the force stops acting (b) the distance covered in 10 s after the force starts acting.
Q 41.
Two objects of masses 100 g and 200 g are moving along the same line in the same direction with velocities of 2 m/s and 1 m/s,respectively.They collide and after the collision, the first object moves at a velocity of 1.67 m/s in the same direction.Determine the velocity of the second object
Q 42.
A hammer of mass 500 g,moving at 50 m/s,strikes a nail.The nail stops the hammer in a very short time of 0.01 s.What is the force of the nail on the hammer ?
Q 43.
Derive the unit of force using the second law of motion. A force of 5 N produces an acceleration of
on a mass
and an acceleration of 24
on a mass
.What acceleration would the same force provide if both the masses are tied together ?
Q 44.
Define momentum of a body.
Q 45.
A ball is thrown vertically upwards. What is its momentum at the highest point ?
Q 46.
What is one newton force ?
Q 47.
Discuss briefly Galileo's ideas about motion.
Q 48.
Establish relation between inertia and mass.
Q 49.
State and deduce the principle of conservation of momentum.
Q 50.
Honey and Sunny are two friends.Both are financially well off.Honey is fond of driving an SUV while Sunny enjoys driving Tata Nano.Honey explains to Sunny the risks of driving a light vehicle and Sunny explains to Honey the cost factor.
Read the above passage and answer the following questions :
(i) With whom do you agree,with Honey or with Sunny?
(ii) Explain, why?
(iii) Which values of life do you learn from this discussion?
