Question:
What do you mean by an imapct force?
Answer:
The force produced by the impact of a fast moving object on another is called impact force.
Force and Laws of Motion
Q 1.
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 2.
When a carpet is beaten with a stick, dust comes out of it. Explain.
Q 4.
A stone of 1 kg is thrown with a velocity if 20
across the frozen surface of a lake and comes to rest after travelling a distance of 50 m.What is the force of friction between the stone and the ice ?
Q 5.
State Newton’s three laws of motion.
Q 6.
Why do we tend to fall outwards when a car takes a steep turn?
Q 7.
What would be the force required to produce an acceleration of 2
in a body of mass 12 kg ? What would be the acceleration if the force were doubled ?
Q 8.
Justify Newton's first law gives notion (or definition) about force.
Q 9.
Why is it advised to tie any luggage kept on the roof of a bus with a rope?
Q 10.
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 11.
Force can change the shape and size of an object. Give an example.
Q 12.
When a force acts on a body, what are the two essential effects it can produce?
Q 14.
What is one newton force ?
Q 15.
Derive the relation F = ma,where the symbols have their usual meanings.
Q 16.
While catching a fast moving ball, fielder gradually pulls his hand backwards. Give reasons.
Q 17.
State Law of conservation of momentum.
Q 18.
Fill in the blanks :
When a hanging carpet is beaten with stick, the dust particles start coming out of it. It is due to ______________.
Q 19.
What are unbalanced forces?
Q 20.
What do you mean by an imapct force?
Q 21.
A force of 5 N gives a mass
an acceleration of 10
,and a mass
,an acceleration of 20
.What acceleration would it give if both the masses were tied together ?
Q 22.
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 23.
A hockey ball of mass 200 g travelling at 10 m/s is struck by a hockey stick so as to return it along its original path with a velocity of 5 m/s.Calculate the change in momentum of the hockey ball by the force applied by the hockey stick.
Q 24.
What is the SI unit of force ?
Q 25.
Is momentum a scalar or vector ?
Q 26.
Define momentum of a body.
Q 27.
An unloaded truck weighing 2000 kg has a maximum acceleration of 0.4
.What is the maximum acceleration, when it carries a load of 2000 kg ?
Q 28.
Explain what is meant by momentum of a body.Is it a scalar or a vector ? What are its units ?
Q 29.
Establish relation between inertia and mass.
Q 30.
Why does a gun recoil on firing ? Obtain an expression for recoil velocity of gun.
Q 31.
State Newton’s first law of motion. Hence define force and inertia.
Q 32.
State Newton’s second law of motion and establish that F = ma where symbols have their usual meanings.
Q 33.
Give atleast four applications of Newton’s second law of motion.
Q 34.
State and explain Newton’s third law of motion.How will you prove it experimentally ?
Q 35.
Explain briefly any three applications of Newton’s third law of motion.
Q 36.
Which of the following has more inertia:
(a) a rubber ball and a stone of the same size?
(b) A bicycle and a train?
(c) A five-rupee coin and a one-rupee coin?
Q 37.
State Newton's First Law of motion.
Q 38.
Explain why some of the leaves may get detached from a tree if we vigorously shake its branch.
Q 39.
Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest?
Q 40.
Is force required to keep a moving object in motion (yes/no)?
Q 42.
Which is having higher value of momentum ? A bullet of mass 10 g moving with a velocity of 400 m/s or a cricket ball of mass 400 g thrown with the speed of 90 km/hr.
Q 43.
What are balanced and unbalanced forces?
Q 44.
If the set of forces acting on an object are balanced, then object
(a) must be at rest.
(b) must be moving
(c) must not be accelerating.
(d) none of these.
Q 45.
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 46.
Which of the following graph represents unbalanced force.
Q 47.
Define 1N (Newton).
Q 48.
What is the unit of force in c.g.s system?
Q 49.
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 50.
How Newton's Second law of motion is different from First law?