A rocket with a mass of 0.5kg is travelling at 400m/s strikes and sticks in a block of wood with a mass of 50kg. find velocity of rocket.

36.36 m/s

Explanation:

From the question,

Applying the law of conservation of momentum.

Total momentum before collision = Total momentum after collision .

mu+m'u' = V(m+m') Equation 1

Where m = mass of the rocket, m' = mass of the wood, u = initial velocity of the rock, u' = initial velocity of the wood, V = Final velocity after collision

But, the wood was initially at rest

Therefore, u' = 0 m/s

mu = V(m+m')

make V the subject of the equation

V = mu/(m+m') Equation 2

Given: m = 0.5 kg, u = 400 m/s, m' = 50 kg

Substitute these values into equation 2

V = (0.5×400)/(0.5+50)

V = 200/5.5

V = 36.36 m/s

i think the answer is b

c)as speed changes, wavelength and frequency change.

everything changes!