Related InterviewSolutions

• A spring which is kept comprassed by tying its ends together is allowed to be dissolved in an acid. What happens to the potnetial energy of the spring ?
• An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy ? If the object is allowed to fall, find its kinetic energy when it is half - way down.
• A body dropped from a height H reaches the ground with a speed of 1.2 `sqrt(gH)`. Calculate the work done by air friction.
• Two idential objects made of iron and wood, are allowed to fall from the same height on a heap of sand. It is found that the iron object penetrates more in the wooden object. Which of the two objects has more potential energy ?
• When an arrow is shot from a bow, it has kinetic energy. From where does it get the kinetic energy ?
• A bullet of mass 5 g travels with a speed of 500m/s. If it penetrates a fixed target which offers a constant resistive force of 1000N to the motion of the bullet, find (a) the initial kinetic energy of the bullet (b) the distance through which the bullet has penetrated.
• (a) Which of the following does the most work : a force of 3N acting through a distance of 3 m or a force of 4N acting through a distnace of 2m? (b) How much work is done by the centripetal force?
• Certain force acting on a 20 kg mass changes its velocity from `5m//s to 2m//s`. calculate the work done by the force.
• A force of 5 N is acting on an object. The object is displaced through 2m in the direction of the force, if the forec acts all through the displacement, find the work done by the force.
• A bullet of mass 20g is found to pass two points 30m apart in 4 s? Assuming the speed to be constant, find its kinetic energy?