Question

A car of mass 500kg is traveling down the road at a constant speed. if this car has a KE=25000J how fast is it going?

a
100 m/s
b
20 m/s
c
10 m/s
d
50 m/s

Answer 1

10 m/s

Step-by-step explanation:

Kinetic energy is:

KE = ½ mv²

Plug in values and solve:

25,000 J = ½ (500 kg) v²

v = 10 m/s

Answer 2

Using the kinetic energy formula KE = 1/2 m v^2, the velocity (v) is calculated as the square root of 2 times the kinetic energy divided by the mass. For a car with mass 500kg and kinetic energy of 25,000J, the speed is 10 m/s.

Step-by-step explanation:

To determine how fast a car of mass 500kg is going when it has kinetic energy (KE) of 25,000J, we can use the formula for kinetic energy:

KE = ½ m v²

where KE is kinetic energy, m is mass, and v is velocity. We rearrange the equation to solve for v:

v = √(2×KE/m)

Plugging in the known values (KE = 25,000J, m = 500kg):

v = √(2×25,000J / 500kg)

v = √(50,000J / 500kg)

v = √(100J/kg)

v = 10 m/s

Therefore, the car is traveling at a speed of 10 m/s.