Question

Q. 4: Two cars are moving with velocities of 36 km/h and 54 km/h on a highway. Find the ratio of
kinetic energies if mass of the cars are 400 kg and 600 kg respectively.
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Answer 1

Answer:

m1 = 400 kg

m2 = 600 kg

v1 = 36 km/hr.

v2 = 54 km/hr.

K.E.1 / k.E.2 = ?

Kinetic energy = 1/2 (mv²)

K.E.1 = 1/2 [m1(v1)²]

= 1/2 [400 (36)²]

= 259200 J

K.E.2 = 1/2 [m2(v2)²]

= 1/2 [600 (54)²]

= 874800 J

K.E.1 / K.E.2 = 259200 / 874800

= 8 / 27 J

Ratio = 8 : 27

Answer 2

Answer:

1. 6400 and 2. 16200

Explanation:

Because the formula of kinetic energy = 1/2 m v square