If a semi-truck decreases its speed from 10 m/s to 5 m/s, its new kinetic energy is:

Question

Physics

Nibbles

5 April, 00:50

If a semi-truck decreases its speed from 10 m/s to 5 m/s, its new kinetic energy is:

+5

Answers (1)

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Tania Sampson · Answer 1

Answer is: 1/4 its old kinetic energy.

V₁ = 10 m/s.

V₂ = 5 m/s.

m₁ = m₂ = m.

E₁ = 1/2 · m₁ · V₁², E₁ = 1/2 · m · (10 m/s) ² = 50 · m.

E₂ = 1/2 · m₂ · V₂², E₂ = 1/2 · m · (5 m/s) ² = 12,5 · m.

E₂/E₁ = 12,5m / 50m = 0,25.

V - speed of semi-truck.

m - mass of semi-truck.

E - kinetic energy of semi-truck.