Question

A certain farce act on
mass 2kg changes its speed from
36kmlh to 54 Km/h in 5 second find
a) Initial momentum
b) final momentum
c)Rate of change of momentum
d)Applied force
e) Impulse​

Answer 1

A certain force act on  mass 2kg changes its speed from  36km/h to 54 Km/h in 5 second.

mass, m = 2 kg

initial speed, u = 36 km/h = 36 × 5/18 = 10 m/s

final speed, v = 54 km/h = 54 × 5/18 = 15 m/s

time taken, t = 5 s

a) Initial momentum  = mu = 2 × 10 = 20 kg.m/s

b) final momentum  = mv = 2 × 15 = 30 kg.m/s

c) Rate of change of momentum  = (mv-mu)/t = (30-20)/5 = 2 kg.m/s²

d) Applied force  = Rate of change of momentum = 2 kg.m/s² = 2 N

e) Impulse​ = Change in momentum = mv- mu = 30-20 = 10 kg.m/s

Answer 2

Answer:

A certain force act on mass 2kg changes its

speed from 36km/h to 54 Km/h in 5 second.

mass, m = 2 kg

initial speed, u = 36 km/h = 36 × 5/18 = 10 m/s

final speed, v = 54 km/h = 54 × 5/18 = 15 m/s

time taken, t=5~s

a) Initial momentum = mu = 2 × 10 = 20 kg.m/s

b) final momentum = mv = 2 x 15 = 30 kg.m/s

c) Rate of change of momentum = = (mv-mu)/t =

(30-20)/5 = 2 kg.m/s²

d) Applied force = Rate of change of momentum

= 2 kg.m/s² = 2 N

e) Impulse = Change in momentum = mv- mu

30-20 = 10 kg.m/s