Force and Laws of Motion
Fill in the blanks
1. The study of motion of a body under the action of a force is called ______.
2. (Impulse/Force/Pressure) ______ is a push or pull acting upon an object.
3. The natural tendency of objects to resist a change in their state of rest or of uniform motion is called ______.
4. When the resultant of all the forces acting on a body is zero, the forces are _______ (balanced/unbalanced).
5. When The resultant of all the forces acting on a body is not zero, the forces are _______ (balanced/unbalanced).
6. Newton’s first law of motion states that a body at rest will remain at _____ (rest/motion) and a body in motion will remain in ________ (uniform/non-uniform) motion unless acted upon by an
_________ (balanced/unbalanced) force.
7. The ______ of an object is a measure of its inertia.
8. _________ (Nuclear/Gravitational/Muscular) Force is the weakest force
9. _______ (Nuclear/Gravitational/Muscular) force is the strongest force of all the basic forces in nature.
10. An imaginary co-ordinate system which is either at rest or in uniform and where Newton’s laws are valid is called an _______ frame of reference.
11. (Centrifugal/Centripetal) ________ force is the apparent outward force that draws a rotating body away from the center of rotation.
12. The radially inward force towards the centre which continuously deflects a particle from its straight line path and makes it along a circular path is called _______ (centrifugal/centripetal) force.
13. The momentum of an object is the product of its _____ and _______ and has the same direction as that of the ________.
14. 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 ______.
15. Action and reaction forces act on ________ (the same body/two different bodies) but they are ______ (equal/unequal) in magnitude.
16. When the resultant force acting on a system is zero , the total momentum of the system ______ (remains constant/ may vary). This is called ___________________ .
17. The velocity with which gun moves in the backward direction is known as the ______ velocity.
18. When the lift is stationary or moves with uniform velocity then acceleration is zero and
net force is ______ (zero/non-zero).
19. A change in momentum over a longer time requires ______ (less/more) force
6. rest, uniform, unbalanced
13. mass, velocity, velocity
14. momentum, force
15. two different bodies, equal.
16. remains constant, law of conservation of linear momentum