The speed of a 4000-kg truck whose KE is 1.8 MJ is
A)0.95 m/s.
B)30 m/s.
C)94 m/s.
D)900 m/s.

Question

Quizplus · Accepted Answer

The formula for kinetic energy is KE = (1/2) * m * v^2, where m is the mass of the object and v is its velocity.

We are given the mass of the truck, 4000 kg, and its KE, 1.8 MJ (1 MJ = 1,000,000 J).

Substituting these values into the formula, we can solve for v:

1.8 MJ = (1/2) * 4000 kg * v^2

1.8 MJ = 2000 kg * v^2

v^2 = 900 J/kg

v = sqrt(900) = 30 m/s

Therefore, the speed of the truck is 30 m/s.

The other answer choices are not valid because they are either too low (A) or too high (C and D) compared to the realistic speed of a truck on the road.

The Speed of a 4000-Kg Truck Whose KE Is 1