Answer:
T = 190 N
Explanation:
When child is sitting on the swing then the weight of the child is vertically downwards
So it is

now a force of 100 N is acting on the swing in horizontal direction
so it is given as

now the net force is resultant force due to gravity and horizontal force
so it is given as



The "i" component of a vector is in the x-direction. Therefore, the x-component is 3 m/s.
Answer:
B.7.5m/s2
Explanation:
average acceleration=change invelocity/time taken
a=(60-30)/4
=7.5m/s2
Answer:
B. When the racket hits the tennis ball with a force, the tennis ball applies an equal but opposite force to the racket.
Explanation:
According to the Newton's third law of motion every action has equal and opposite reaction. So, when the force is applied by the racket on the ball then the ball also applies an equal intensity of force in the opposite direction on the racket. It is just that the the force on the racket is absorbed by the player holding it.