Answer:A
Explanation:Find attached picture file for details
Answer:
-58.8 J
Explanation:
The work done by a force is given by:

where
F is the magnitude of the force
d is the displacement of the object
is the angle between the direction of the force and the displacement.
In this problem, we are asked to find the work done by gravity, so we must calculate the magnitude of the force of gravity first, which is equal to the weight of the object:

The displacement of the object is d = 3.00 m, while
, because the displacement is upward, while the force of gravity is downward; therefore, the work done by gravity is

And the work done is negative, because it is done against the motion of the object.
Answer:
The tension in the string is quadrupled i.e. increased by a factor of 4.
Explanation:
The tension in the string is the centripetal force. This force is given by

m is the mass, v is the velocity and r is the radius.
It follows that
, provided m and r are constant.
When v is doubled, the new force,
, is

Hence, the tension in the string is quadrupled.
Answer:
upward force acting = 261.6 N
Explanation:
given,
mass of gibbon = 9.4 kg
arm length = 0.6 m
speed of the swing
net force must provide

force of gravity = - mg

= 
= 
=9 x 29.067
= 261.6 N
upward force acting = 261.6 N
Answer:
0.50m/s
Explanation:
Average velocity is the change in displacement of a body with respect to time.
Velocity = ∆S/∆t
∆S = 100m - 70m
∆S = 30m
∆t = 2min - 1 min
∆t = 1min = 60secs
Substitute the given parameters into the formula for velocity
Velocity = 30m/60s
Velocity = 1/2 m/s
Average Velocity = 0.5m/s