The potential energy of a long spring when stretched by 2 cm is U if the spring you stretched by 8 cm potential energy stored in it will be

• 8U

• 16U

• 2U

• 4U

An electric lift with a maximum load of 2000 kg is moving up with the constant speed of 1.5 MS ^-1 the frictional force opposite in the motion is 3000 in the minimum power delivered by the motor lift in Watts is

• 23000

• 34500

• 20000

• 23500

A particle is released from height us from the surface of the earth at a certain height it's kinetic energy is three times its potential energy the height from the surface of earth and the speed of the particle at that respectively

• S/4, √3gs/2

• S/4, 3gs/2

• S/4√3gs/2

• S/2, √3gs/2

Waterfalls from my height of a 60m at the rate of 50 kg by yes to operate a turbine the losses due to fictional force or 10% of the input energy how much power is generator by the turbine

• 7.0kw

• 10.2 w

• 8.1kw

• 12.3

The energy required to break 1 pound in DNA is 10 ^-20 J the value in Ev is nearly

• 6

• 0.6

• 0.06

• 0.006

Force f equal to 20 + 10y acts on a particle in Y direction where f is in Newton and Y in M work done by this 4C to move the particle from y=o to y = 1 m is

• 20j

• 30j

• 5j

• 25j

A mass M is attached to your thin wire and whireled invertical circle the wire is most likely to break when

• Inclined at on angle of 60^° from vertical

• The mass is at the highest point

• The wire is is horizontal

• The mass at the lowest point

Body of mass 4 m moving with speed you colleagues with another body be of mass 2 m at rest the collision is head on head elastic in nature after the collision of the fraction of energy lost by the colliding bodyA

• 5/9

• 1/9

• 8/9

• 4/9

A particle mass 5 m rest suddenly bridge on its own into three fragment two fragments of mass along usually perpendicular direction with speed V the energy released during the process

• 3/5 mv²

• 5/3mv²

• 3/2mv²

• 4/3mv²

If potential energy is given by U=a/r²- b/r then find out maximum force

• -16/27 N

• -32/27 N

• +32/27 N

• +16/27 N