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 man places a chain of mass ′m′ and length ′l′ on a table slowly. Initially, the lower end of the chain just touches the table. The man drops the chain when half of the chain is in the vertical position. Then work done by the man in this process is?
27
Nov
A man places a chain of mass ′m′ and length ′l′ on a table slowly. Initially, the lower end of the chain just touches the table. The man drops the chain when half of the chain is in the vertical position. Then work done by the man in this process is? A man places a [...]
A particle of mass m moves along a circular path of radius r with a centripetal acceleration an changing with time t as an=kt2, where k is a positive constant. The average power developed by all the forces acting on the particle during the first t0 seconds is.
27
Nov
A particle of mass m moves along a circular path of radius r with a centripetal acceleration an changing with time t as an=kt2, where k is a positive constant. The average power developed by all the forces acting on the particle during the first t0 seconds is. A particle of mass m moves along [...]
Figure shows a smooth vertical circular track AB of radius R. A block slides along the surface AB when it is given a velocity equal to 6gR−−−−√ at point A. The ratio of the force exerted by the track on the block at point A to that at point B is
20
Oct
Figure shows a smooth vertical circular track AB of radius R. A block slides along the surface AB when it is given a velocity equal to 6gR−−−−√ at point A. The ratio of the force exerted by the track on the block at point A to that at point B is A person of mass [...]
A small sphere is given vertical velocity of magnitude v0 = 5 ms^−1 and it swings in a vertical plane about the end of a massless string. The angle θ with the vertical at which string will break, knowing that it can withstand a maximum tension equal to twice the weight of the sphere, is
20
Oct
A small sphere is given vertical velocity of magnitude v0 = 5 ms^−1 and it swings in a vertical plane about the end of a massless string. The angle θ with the vertical at which string will break, knowing that it can withstand a maximum tension equal to twice the weight of the sphere, is [...]
A bead of mass 1/2 kg starts from rest from A to move in a vertical plane along a smooth fixed quarter ring of radius 5 m, under the action of a constant horizontal force F = 5 N as shown in Fig. The speed of bead as it reaches point B is
20
Oct
A bead of mass 1/2 kg starts from rest from A to move in a vertical plane along a smooth fixed quarter ring of radius 5 m, under the action of a constant horizontal force F = 5 N as shown in Fig. The speed of bead as it reaches point B is A bead [...]
Two bodies of masses m and 4 m are attached to a light string as shown in figure. A body of mass m hanging from string is executing oscillations with angular amplitude 60^∘, while other body is at rest on a horizontal surface. The minimum coefficient of friction between mass 4m and the horizontal surface is (here pulley is light and smooth)
20
Oct
Two bodies of masses m and 4 m are attached to a light string as shown in figure. A body of mass m hanging from string is executing oscillations with angular amplitude 60^∘, while other body is at rest on a horizontal surface. The minimum coefficient of friction between mass 4m and the horizontal surface [...]
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Two bodies of masses m and 4 m are attached to a light string as shown in figure. A body of mass m hanging from string is executing oscillations with angular amplitude 60^∘ ,
while other body is at rest on a horizontal surface. The minimum coefficient of friction between mass 4m and the horizontal surface is (here pulley is light and smooth) ,
A bead of mass m is released from rest at A to move along the fixed smooth circular track as shown in figure. The ratio of magnitudes of centripetal force and normal reaction by the track on the bead at any point P0 described by the angle θ(≠0) would
20
Oct
A bead of mass m is released from rest at A to move along the fixed smooth circular track as shown in figure. The ratio of magnitudes of centripetal force and normal reaction by the track on the bead at any point P0 described by the angle θ(≠0) would A person of mass 70kg jumps [...]
A block of mass m is lying at rest at point P of a wedge having a smooth semi-circular track of radius R. What should be the minimum value of a0 so that the mass can just reach point Q
20
Oct
A block of mass m is lying at rest at point P of a wedge having a smooth semi-circular track of radius R. What should be the minimum value of a0 so that the mass can just reach point Q A block of mass m is lying at rest at point P of a wedge [...]
A particle of mass m slides along a curved-flat-curved track. The curved portions of the track are smooth. If the particle is released at the top of one of the curved portions, the particle comes to rest at flat portion of length l and of μ = μkinetic after covering a distance of
20
Oct
A particle of mass m slides along a curved-flat-curved track. The curved portions of the track are smooth. If the particle is released at the top of one of the curved portions, the particle comes to rest at flat portion of length l and of μ = μkinetic after covering a distance of A particle [...]
A mass m starting from A reaches B of a frictionless track. On reaching B, it pushes the track with a force equal to x times its weight, then the applicable relation is
20
Oct
A mass m starting from A reaches B of a frictionless track. On reaching B, it pushes the track with a force equal to x times its weight, then the applicable relation is A mass m starting from A reaches B of a frictionless track. On reaching B it pushes the track with a force [...]