Supply the missing term/s to complete the sentences.
1. When a force is exerted on an object, its ____ changes
2. When a person walks northward, the direction of friction is ____
3. Newton is a unit of force which is equivalent to ____
4. A person weighing 588 N has a mass of _____
5. A person pushing a wall wearing roller skates tends to move backwards because of Newton's law of _____
6. If it took 70 N to move a body at a constant speed of 7 m/s, the force
needed to maintain that speed is _____
7. The centripetal force on a child riding a swing is _____
8. If you cut the string of a whirling can, the can goes in the ____ direction.
9._____ is the tendency of an object to resist changes in motion.
10. When a force applied on an object halves, its acceleration ______
Answers
Answer:
1 : A force arises due to the interaction between two objects. Force has magnitude as well as direction. A change in the speed of an object or the direction of its motion or both implies a change in its state of motion. Force acting on an object may cause a change in its state of motion or a change in its shape.
2 : When we walk, our feet are pushing backwards and therefore the friction opposes the pushing and acts in the opposite direction which happens to be the direction in which we are walking
3 : One newton equals a force that produces an acceleration of one meter per second (s) per second on a one kilogram (kg) mass. Therefore, one joule equals one newton•meter
4 : The weight of a man on the surface of Earth is 588 N. Find his mass, taking g=9.8m/s2. If the man were taking to Moon, his weight would be 98 N.
5 : 'Galileo's law of inertia' is the other name for Newton's first law of motion.
6 : (in picture given above)
7 : The tension force in the string of a swinging tethered ball and the gravitational force keeping a satellite in orbit are both examples of centripetal forces.
8 : When the boy is whirling a stone tied with a string in a circular path, the centripetal force acts towards the center of the circular path. However, when the string breaks the centripetal force ceases and there is no force acting. Thus, the stone as per Newtons first law will continue in a straight line and fly off along the tangent to the circular path.
9 : Inertia - Inertia is the tendency of an object to resist motion.
10 : A force applied on an object can change its state of rest or motion and its shape or size.
