Answer:
Option A. 4 m
Explanation:
Please see attached photo for diagram.
In the attached photo, X is the distance from the centre to which the student on the right must sit in order to balance the seesaw.
Clockwise moment = X × 45
Anticlock wise moment = 3 × 60
Clockwise moment = Anticlock wise moment
X × 45 = 3 × 60
X × 45 = 180
Divide both side by 45
X = 180 / 45
X = 4 m
Thus, the student must sit at 4 m from the centre.
Answer:
Part a)
a = -9.81 m/s/s
Part b)
v = 0
Part c)
v = 9.81 m/s
Part d)

Explanation:
Part a)
During the motion of ball it will have only gravitational force on the ball
so here the acceleration of the ball is only due to gravity
so it is given as

Part b)
As we know that ball is moving against the gravity
so here the velocity of ball will keep on decreasing as the ball moves upwards
so at the highest point of the motion of the ball the speed of ball reduce to zero

Part c)
We know that the total time taken by the ball to come back to the initial position is T = 2 s
so in this time displacement of the ball will be zero



Part d)
at the maximum height position we know that the final speed will be zero
so we will have

here we have

