FORCE

1.FILL IN THE BLANKS

a. The momentum of an object is product of its mass and ……………..

b. According to second law of motion “the rate of change of momentum is directly proportional to ……………… applied”.

c. According to law of conservation of momentum “the total momentum of an isolated system is always ……………..

d. The forces are said to be balanced, if net force is ……………..

e. According to third law of motion “to every action there is an equal and ……………… reaction and they act on two different bodies”.

2.MATCH THE FOLLOWING.

(a) Action and reaction (i) Balanced forces

(b) Cricket player lowers his hand while catching the ball (ii) Newton’s first law

(d) Resultant force is zero (iv) Newton’s second law

(e) A ball thrown upward in a train moving with uniform velocity returns to the thrower. (v) Inertia

(f) SI unit of momentum (vi) Newton’s third law

(g) Tendency of a body to resist change in its state of motion or rest. (vii) Conservation of linear momentum

(h) Inertia of a body depends on it (viii) kg m/s²

3.Inertia is the property of a body by virtue of which, it cannot change by itself

(a) its state of rest

(b) its steady state of uniform motion

(d) all of these.

4.Which of the following is an incorrect statement?

(a) Mass is measure of inertia of a body.

(b) Newton’s first law of motion is the law of inertia.

(d) Newton’s third law talks about the direction of the force.

5.If the mass of a body is doubled and its velocity becomes half, then the linear momentum of the body will

(a) remain same

(b) become double

(d) become four times.

6.Rocket works on the principle of conservation of

(a) mass

(b) energy

(d) velocity