Question

A block having mass of 5 kg has a velocity of 15 m/sec horizontally on a smooth frictionless

surface. Determine the value of the horizontal force to be applied to the block for bringing the

block to rest in 5 seconds.​

Answer 1

A block having mass of 5 kg has a velocity of 15 m/sec horizontally on a smooth frictionless

surface. Determine the value of the horizontal force to be applied to the block for bringing the

block to rest in 5 seconds.

Answer 2

Answer:

Correct option is A

kinetic energy of block = work done by friction + potential energy of spring

2

1 mv 2 =f.x+1 kx2

2

equation 1

frictional force

f=μmg=0.1×50×10=50

Initial velocity =2 m/s k=100

by putting all these values in equation 1

we get,

2

1

×50×(2)

2

=50x+

2

1

×100×x

2

⇒x

2

+x−2=0

by solving this equation we get

x=1,x=−2

x=−2 is not possible

then x=1

thus the maximum compression of spring is 1m