A spy jumps from an airplane with his pasrachute. The spy accelerates downward for some time when the parachute opens. The acceleration is sudenly checked and the spy slowly falls on the ground. Explain the action of parachute in checking the acceleration.

A lift accelerates downwards from rest at rate of 2 m//s^(2) , starting 100 m above the ground. After 3 sec, an object falls out of the lift. Which will reach the ground first? What is the time interval between their striking the ground?

An object A is kept fixed at the point x= 3 m and y = 1.25 m on a plank p raised above the ground . At time t = 0 the plank starts moving along the +x direction with an acceleration 1.5 m//s^(2) . At the same instant a stone is projected from the origin with a velocity vec(u) as shown . A stationary person on the ground observes the stone hitting the object during its downward motion at an angle 45(@) to the horizontal . All the motions are in the X -Y plane . Find vec(u) and the time after which the stone hits the object . Take g = 10 m//s

A circus wishes to develop a new clown act. Fig. (1) shows a diagram of the proposed setup. A clown will be shot out of a cannot with velocity v_(0) at a trajectory that makes an angle theta=45^(@) with the ground. At this angile, the clown will travell a maximum horizontal distance. The cannot will accelerate the clown by applying a constant force of 10, 000N over a very short time of 0.24s . The height above the ground at which the clown begins his trajectory is 10m . A large hoop is to be suspended from the celling by a massless cable at just the right place so that the clown will be able to dive through it when he reaches a maximum height above the ground. After passing through the hoop he will then continue on his trajectory until arriving at the safety net. Fig (2) shows a graph of the vertical component of the clown's velocity as a function of time between the cannon and the hoop. Since the velocity depends on the mass of the particular clown performing the act, the graph shows data for serveral different masses. From figure 2, approximately how much time will it take for clown with a mass of 60 kg to reach the safety net located 10 m below the height of the cannot?

A circus wishes to develop a new clown act. Fig. (1) shows a diagram of the proposed setup. A clown will be shot out of a cannot with velocity v_(0) at a trajectory that makes an angle theta=45^(@) with the ground. At this angile, the clown will travell a maximum horizontal distance. The cannot will accelerate the clown by applying a constant force of 10, 000N over a very short time of 0.24s . The height above the ground at which the clown begins his trajectory is 10m . A large hoop is to be suspended from the celling by a massless cable at just the right place so that the clown will be able to dive through it when he reaches a maximum height above the ground. After passing through the hoop he will then continue on his trajectory until arriving at the safety net. Fig (2) shows a graph of the vertical component of the clown's velocity as a function of time between the cannon and the hoop. Since the velocity depends on the mass of the particular clown performing the act, the graph shows data for serveral different masses. If a clown holds on to hoop instead of passing through it, what is the position of the cable so that he doesn't hit his head on the ceiling as he swings upward?

A circus wishes to develop a new clown act. Fig. (1) shows a diagram of the proposed setup. A clown will be shot out of a cannot with velocity v_(0) at a trajectory that makes an angle theta=45^(@) with the ground. At this angile, the clown will travell a maximum horizontal distance. The cannot will accelerate the clown by applying a constant force of 10, 000N over a very short time of 0.24s . The height above the ground at which the clown begins his trajectory is 10m . A large hoop is to be suspended from the celling by a massless cable at just the right place so that the clown will be able to dive through it when he reaches a maximum height above the ground. After passing through the hoop he will then continue on his trajectory until arriving at the safety net. Fig (2) shows a graph of the vertical component of the clown's velocity as a function of time between the cannon and the hoop. Since the velocity depends on the mass of the particular clown performing the act, the graph shows data for serveral different masses. If the mass of a clown doubles, his initial kinetic energy, mv_(0)^(2)//2 , will :-

A circus wishes to develop a new clown act. Fig. (1) shows a diagram of the proposed setup. A clown will be shot out of a cannot with velocity v_(0) at a trajectory that makes an angle theta=45^(@) with the ground. At this angile, the clown will travell a maximum horizontal distance. The cannot will accelerate the clown by applying a constant force of 10, 000N over a very short time of 0.24s . The height above the ground at which the clown begins his trajectory is 10m . A large hoop is to be suspended from the celling by a massless cable at just the right place so that the clown will be able to dive through it when he reaches a maximum height above the ground. After passing through the hoop he will then continue on his trajectory until arriving at the safety net. Fig (2) shows a graph of the vertical component of the clown's velocity as a function of time between the cannon and the hoop. Since the velocity depends on the mass of the particular clown performing the act, the graph shows data for serveral different masses. If the angle the cannot makes with the horiaontal is increased from 45^(@) , the hoop will have to be

A circus wishes to develop a new clown act. Fig. (1) shows a diagram of the proposed setup. A clown will be shot out of a cannot with velocity v_(0) at a trajectory that makes an angle theta=45^(@) with the ground. At this angile, the clown will travell a maximum horizontal distance. The cannot will accelerate the clown by applying a constant force of 10, 000N over a very short time of 0.24s . The height above the ground at which the clown begins his trajectory is 10m . A large hoop is to be suspended from the celling by a massless cable at just the right place so that the clown will be able to dive through it when he reaches a maximum height above the ground. After passing through the hoop he will then continue on his trajectory until arriving at the safety net. Fig (2) shows a graph of the vertical component of the clown's velocity as a function of time between the cannon and the hoop. Since the velocity depends on the mass of the particular clown performing the act, the graph shows data for serveral different masses. If the clown's mass is 80 kg , what initial velocity v_(0) will have as he leaves the cannot?

A circus wishes to develop a new clown act. Fig. (1) shows a diagram of the proposed setup. A clown will be shot out of a cannot with velocity v_(0) at a trajectory that makes an angle theta=45^(@) with the ground. At this angile, the clown will travell a maximum horizontal distance. The cannot will accelerate the clown by applying a constant force of 10, 000N over a very short time of 0.24s . The height above the ground at which the clown begins his trajectory is 10m . A large hoop is to be suspended from the celling by a massless cable at just the right place so that the clown will be able to dive through it when he reaches a maximum height above the ground. After passing through the hoop he will then continue on his trajectory until arriving at the safety net. Fig (2) shows a graph of the vertical component of the clown's velocity as a function of time between the cannon and the hoop. Since the velocity depends on the mass of the particular clown performing the act, the graph shows data for serveral different masses. The slope of the line segments plotted in figure 2 is a figure constant. Which one of the following physical quantities does this slope represent?

A ball is dropped from the top of a building. The ball takes 0.50 s to fall past the 3m length of a window, which is some distance below the top of the building. (a) How fast was the ball going as it passed the top of the window? (b) How far is the top of the window from the point at which the ball was dropped? Assume acceleration g in free fall due to gravity to be 10 m//s^(2) downwards.

The rear side of a truck is open and a box of mass 20kg is placed on the truck 4m away from the open end mu = 0.15 and g = 10m//s^(2) The truck starts from rest with an acceleration of 2m//s^(2) on a straight road The box will fall off the truck when it is at a distance from the starting point equal to .