Question

what is work to be done to increase the velocity of a car from 36km/h to 72km/h if the man of the car is 1400k​

Answer 1

Correct Question :-

• What is the work done to increase a the velocity of a car from 36 km/hr to 72 km/hr, if mass of car is 1400 kg

Given :-

• Initial Velocity (u) = 36 km/hr
• Final Velocity (v) = 72 km/hr
• Mass (m) = 1400 kg

Converting Initial Velocity & Final Velocity to m/s which is in km/hr

For Converting from km/hr to m/s

We simply multiply by 5/18

∵ u = 36 km/hr

→ 36 × 5/18

→ 2 × 5

→ 10

∴ 10 m/s

∵ v = 72 km/hr

→ 72 × 5/18

→ 4 × 5

→ 20

∴ 20 m/s

To Find :-

• Work Done

Formula Used :-

• ½ m(v² - u²)

⟹ ½ × 1400 (20² - 10²)

⟹ 7000 (400 - 100)

⟹ 7000 × 300

⟹ 2100000

Thus, 2100000 is the work done