Question

23. A particle of mass m is projected with velocity v
making an angle of 45° with the horizontal. When
the particle lands on the level ground the
magnitude of the change in its momentum will be
[AIPMT (Prelims)-2008]
(1) Zero
(2) 2 mv
5/
(4) muſz​

Answer 1

Answer:

Zero

Explanation:

Momentum = mass x velocity

Let M1 be the initial momentum and M2 be the final momentum,

M2 - M1 = m2 v2 - m1 v1

Now mass will remain unchanged.

M2 - M1 = m v2 - m v1

M2 - M1 = m (v2 - v1)

Also magnitude of velocity will remain unchanged, just it's direction will be changed by 90°.

(here v2 ≠ v1 but s2 = s1)

M2 - M1 = m (s2 - s1) = 0

So,

Magnitude of Momentum = mass x speed

As mass and speed are unchanged,

Final and initial magnitude of momentum will be same.