An object thrown at a certain angle to the ground moves in a curved path and fails back to the ground.. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?

What is the work done when the force on the object is zero?

A mass of 10 kg is a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer.

A force of 7 N acts on an object. The displacement it, say 8m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done in this case?

A rain drop of radius 2 mm falls from a height of 500 m above the ground. It falls with decreasing acceleration (due to viscous resistance of the air) until at half its original height, it attains its maximum (terminal) speed, and moves with uniform speed thereafter. What is the work done by the gravitational force on the drop in the first and second half of its journey? What is the work done by the resistive force in the entire journey if its speed on reaching the ground is 10 m s-^1 ?

The angle of elevation of the top of a tower at a point on a level ground is 30°.After walking a distance of 100mtowards the foot of the tower along the horizontal line through the foot of the tower on the same level ground, the angle of elevation of the top of the tower is 60°.Find the height of the tower.

Two heavy spheres each of mass 100 kg and radius 0.10 m are placed 1.0 m apart on a horizontal table. What is the gravitational force and potential at the mid point of the line joining the centers of the spheres? Is an object placed at that point in equilibrium? If so, is the equilibrium stable or unstable?

In an electric filed a unit positive charge is displaced from one point to another point along a straingt line of length 2cm and the work done is 2mJ. If it is displaced along a parabilic path between the same points of length 5 cm, What will be the work done?

Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 m s^-1 before the collision during which they stick together. What will be the velocity of the combined object after collision?

An object moves along a straight line with an acceleration of 2 m/s2. If its initial speed is 10 m/s, what will be its speed 2 s later?