Question

Numericals:-
A motorcar of mass 1200kg is moving along a straight line with a uniform velocity of 90km/h.Its velocity is slowed down to 18km/h in 4s by an unbalanced external force.Calculate the acceleration and change in momentum.Also,Calculate the magnitude of the force required.??

plz help me and give me the correct answer i will mark u as Brainlist..​

Answer 1

Answer:

Mass of the motor car, m = 1200 kg

Initial velocity of the motor car, u = 90 km/h = 25 m/s

Final velocity of the motor car, v = 18 km/h = 5 m/s

Time taken, t = 4 s

Solution:

ΔP = mv − mu

ΔP = 1200 × 5−1200×25 = −24000 kg m/s

v = u + at

5 = 25 + a × 4

⟹ a = −5 m/s2

(-ve shows retardation)

∣F∣ = m∣a∣ =1 200 × 5 = 6000 N

Answer 2

Answer:

Mass of the motor car, m = 1200 kg

Initial velocity of the motor car, u = 90 km/h = 25 m/s

Final velocity of the motor car, v = 18 km/h = 5 m/s

Time taken, t = 4 s

Solution:

ΔP = mv − mu

ΔP = 1200 × 5−1200×25 = −24000 kg m/s

v = u + at

5 = 25 + a × 4

⟹ a = −5 m/s2

(-ve shows retardation)

∣F∣ = m∣a∣ =1 200 × 5 = 6000 N

Explanation:

mark me brilliantly and follow