Answer:
- The gravity does a work of - 117.6 Joules.
- The tension does not do work as the force is perpendicular to the direction of motion at any point in the trajectory.
Explanation:
The work done by the gravity simply is the difference in gravitational potential energy multiplied by -1:

where m is the mass of the ball, g is the acceleration due to gravity,
is the final height and
is the initial height.
So, if the radius is 2.00 m, then the difference of height will be 4 meters:



As the tension is perpendicular to the velocity of the ball, the force is always perpendicular to the direction of motion. So, the differential of work will be:

Answer:
10
Explanation:
(r) = <10 cos 6t, 10 Sin 6t>
The distance traveled by the object is the magnitude of vector r.
The magnitude of vector r is given by


r = 10
Answer:
wrong statement : Momentum is not conserved for a system of objects in a head-on collision.
Explanation:
In a head on collision of two objects , two equal and opposite forces are created at the point of collision . These two forces create two impulses in opposite direction which results in equal and opposite changes in momentum in each of them . Hence net change in momentum is zero. In this way momentum is conserved in head on collision of two objects.
The answer to the question
Velocity, because if an object is in motion with no direction we will consider it as speed, but if it has direction we will consider it as Velocity. Hope it helps