Question

S: 8 A bullet having a mass of 20 g and moving with a speed of 3m/s . penetrates a thick wooden plank of mass 700 g
. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity
​

Answer 1

Explanation:

jwjsjske

s

dksmsksms

s

smkks

Answer 2

mass of bullet=10g=0.01kg

velocity of bullet=1.5

s

m

mass of plank=90g=0.09kg

Total momentum before collision=mass of plank × velocity

=0.01×1.5+0.09×0=0.015kg

s

m

Total momentum after collision=(mass of bullet +mass of plank )× velocity

=0.1kg×V=0.1Vkg

s

m

According to law of conservation of momentum,

Total momentum before collision=Total momentum after collision

0.015kg

s

m

=0.1vkg

s

m

velocity acquired by the plank and the bullet=0.15

s

m