Which of the following statements is/are true?
1. Forces in the same direction add up.
2. Two forces in opposite directions resulting in net force, equal to their difference, in the direction of the larger force.
3. Change in either direction or magnitude of a force changes its effect.
4. When more than one force is acting on an object, the effect on the object is due to the net force acting on it.
All of the above
When you and your friend push a box in the same direction, it is easier to push the box because forces applied by both of you add up to give the required force.
However, when you apply forces in opposite directions, it becomes difficult to push the box because the forces applied by both of you cancel each other. The net force now acting is the difference of the forces applied by you and your friend. Also, the box moves in the direction of the force which has greater magnitude, i.e., in the direction of whoever pushes harder.
When a batsman hits a ball, the movement of the ball depends on both the direction and the magnitude of the force applied by the batsman. Thus, the effect of a force depends on both, the direction and the magnitude of the force. When more than one force is acting on a body, the effect is due to the net force.