How much work must be done on a 5-kg snowboard to increase its speed from 2 m/s to 4 m/s?

A. 22.5 J

B. 40 J

C. 30 J

D. 15 J

Option C = 30 j

Explanation:

Given dа ta:

mass of snowboard = 5 Kg

Initial speed = 2 m/s

final speed = 4 m/s

work done = ΔE=?

ΔE = change in kinetic energy

Solution:

Formula:

K. E (initial) = 1/2 * mv²

K. E (initial) = 1/2 * 5 Kg. (2m/s) ²

K. E (initial) = 1/2 * 20 Kg. m²/s²

K. E (initial) = 10 Kg. m²/s² or 10 J

Kg. m²/s² = J

K. E (finial) = 1/2 * mv²

K. E (finial) = 1/2 * 5 Kg. (4m/s) ²

K. E (finial) = 1/2 * 5 Kg. 16 m²/s²

K. E (finial) = 1/2 * 80 Kg. m²/s²

K. E (finial) = 40 Kg. m²/s² or 40 J

work done = ΔE = K. E (finial) - K. E (initial)

work done = ΔE = 40 J - 10 J

work done = ΔE = 30 J