Chapter 7 – Work, Energy and Power
Sahay Sir > Question Answers > Cengage JEE Mains Physics by B.M Sharma > Chapter 7 - Work, Energy and Power
A toy gun a spring of force constant k. When changed before being triggered in the upward direction, the spring is compressed by a distance x. If the mass of the shot is m, on the being triggered it will go up to a height of
20
Oct
A toy gun a spring of force constant k. When changed before being triggered in the upward direction, the spring is compressed by a distance x. If the mass of the shot is m, on the being triggered it will go up to a height of A toy gun a spring of force constant k. [...]
An object of mass m slides down a hill of arbitrary shape and after travelling a certain horizontal path stops because of friction. The total vertical height descended is h. The friction coefficient is different for different segments for the entire path but is independent of the velocity and direction of motion. The work that a tangential force must perform to return the object to its initial position along the same path is
20
Oct
An object of mass m slides down a hill of arbitrary shape and after travelling a certain horizontal path stops because of friction. The total vertical height descended is h. The friction coefficient is different for different segments for the entire path but is independent of the velocity and direction of motion. The work that [...]
A particle of mass m is moving in a circular path of constant radius r such that centripetal acceleration is varying with time t as k^2 rt^2 , where k is a constant. The power delivered to the particle by the force acting on it is
20
Oct
A particle of mass m is moving in a circular path of constant radius r such that centripetal acceleration is varying with time t as k^2 rt^2 , where k is a constant. The power delivered to the particle by the force acting on it is A particle of mass m is moving in a [...]
The kinetic energy k of a particle moving along a circle of radius R depends on the distance s as KE=as^2 ,The force acting on the particle is
20
Oct
The kinetic energy k of a particle moving along a circle of radius R depends on the distance s as KE=as^2 ,The force acting on the particle is the force acting on the particle is The kinetic energy k of a particle moving along a circle of radius R depends on the distance s as [...]
Figure shows the vertical section of a frictionless surface. A block of mass 2kg is released from rest from position A, its KE as it reaches position C is (g=10ms^−2)
20
Oct
Figure shows the vertical section of a frictionless surface. A block of mass 2kg is released from rest from position A, its KE as it reaches position C is (g=10ms^−2) Figure shows the vertical section of a frictionless surface. A block of mass 2kg is released from rest from position A its KE as it [...]
The velocity-time graph of a particle moving in a straight line is shown in figure. The mass of the particle is 2kg. Work done by all the forces acting on the particle in time interval between t=0 to t=10s is
20
Oct
The velocity-time graph of a particle moving in a straight line is shown in figure. The mass of the particle is 2kg. Work done by all the forces acting on the particle in time interval between t=0 to t=10s is A man M1 of mass 80kg runs up a staircase in 15s. Another man M2 [...]
Power supplied to a mass 2kg varies with time as P=3t^2/2 watt. Here t is in second . If velocity of particle at t=0 is v=0, the velocity of particle at time t=2s will be:
20
Oct
Power supplied to a mass 2kg varies with time as P=3t^2/2 watt. Here t is in second . If velocity of particle at t=0 is v=0, the velocity of particle at time t=2s will be: Power supplied to a mass 2kg varies with time as P=3t^2/2 watt. Here t is in second . If velocity [...]
A heavy weight is suspended from a spring . A person raises the weight till the spring becomes slack . The done by him is W. The energy stored in the stretched spring was E . What will be the gain in gravitational potential energy?
20
Oct
A heavy weight is suspended from a spring . A person raises the weight till the spring becomes slack . The done by him is W. The energy stored in the stretched spring was E . What will be the gain in gravitational potential energy? A man M1 of mass 80kg runs up a staircase [...]
A bus can be stopped by applying a retarding force F when it is moving with speed v on a level road. The distance covered by it before coming to rest is s. If the load of the bus increase by 50% because of passengers, for the same speed and same retarding force, the distance covered by the bus to come to rest shall be
20
Oct
A bus can be stopped by applying a retarding force F when it is moving with speed v on a level road. The distance covered by it before coming to rest is s. If the load of the bus increase by 50% because of passengers, for the same speed and same retarding force, the distance [...]
An engine pumps water continuously through a hole. Speed with which water passes through the hole nozzle is v and k is the mass per unit length of the water jet as it leaves the nozzle. Find the rate at which kinetic energy is being imparted to the water.
20
Oct
An engine pumps water continuously through a hole. Speed with which water passes through the hole nozzle is v and k is the mass per unit length of the water jet as it leaves the nozzle. Find the rate at which kinetic energy is being imparted to the water. A man M1 of mass 80kg [...]