Question

9. Amass of 5kg is attached to a spring of spring constant, k=100N/m is placed on
a smooth horizontal surface. Aforce of 20N is pulling the mass horizontally. What
is the speed of block when extension in spring is 8cm.​

Answer 1

Answer:

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

2

1

mv

2

=f.x+

2

1

kx

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

Explanation:

JUST DO IN THIS WAY YOU WILL GET IT