EFFECTS OF FORCE
• We cannot see force, but we can see its effects. The effects that a force can have on objects are:
• Motion is a change of position.
• When a person throws a ball, he or she puts it in motion and the position of the ball changes.
• When a baseball player runs around the bases, his or her position changes.
• Even, the force applied by the baseball batsman, changes the direction of the ball that is bowled at him/her.
Figure 10: Effect of force observed in baseball
Figure 11: A top spins around and around, a swing moves back and forth, and a clock pendulum moves from side to side, when we do jumping jacks, we move up and down
Figure 12: Chapatti prepared from the dough
• While making chapattis, the force applied by the hands changes the shape of the dough.
Figure 13: A girl is skating on a slanting rod, some shells come in motion after sometime, a red car is stationary and starts moving after sometime, a man is applying force on a machine and machine moves
• For e.g. Take some pennies, marbles, or other small objects and push on the floor or on a flat surface.
• Force changes the motion of body that is already in motion and produce motion in a stationary body.
• A stationary car on a road suddenly gets hit behind by a truck.
• The force applied by the truck affects the position of the car.
• So, we can say that the position of the stationary body (car) changes when it is hit behind by a moving body (truck).
Figure 14: A red car is stationary and starts moving after sometime, a boy is moving a globe
• Speed describes how fast/slow something moves.
• Fast-moving objects go farther distances in a small amount of time.
• Slow-moving objects take much longer to go the same distance.
• We must also know that we need more force to put heavier objects in motion.
Figure 15: A man is typing with the help of a typing machine which starts working after a man is applying some force on it; a boy is pushing a cart with a boy
Figure 16: Balls are not in a stationary mode when they start spinning, a girl is applying force on a ball to cause it to move