Question

In a vehicle traveling at 20 miles per hour, the force of your car impacting a surface is ______ times as great as at 10 mph.

Answer 1

4

Step-by-step explanation

The energy possessed by an object in motion is called kinetic energy.

Kinetic energy (K.E) = 1/2 mv²

Where m is the mass of the body and v is the velocity of the object.

For the vehicle traveling at 20 mph, its energy is;

K.E = 1/2×m×20² = 200m

For the vehicle moving at 10 mph, its energy is;

K.E = 1/2×m×10² = 50m

∴ 200m ÷ 50m = 4

It can be seen that the force of impact is 4 times greater.

I did not consider changing the units of velocity from mph to mps because am comparing the two energies. Even if I convert the velocities to mps, the answer would be same 4 times greater.

Answer 2

4

Step-by-step explanation

The energy possessed by an object in motion is called kinetic energy.

Kinetic energy (K.E) = 1/2 mv²

Where m is the mass of the body and v is the velocity of the object.

For the vehicle traveling at 20 mph, its energy is;

K.E = 1/2×m×20² = 200m

For the vehicle moving at 10 mph, its energy is;

K.E = 1/2×m×10² = 50m

∴ 200m ÷ 50m = 4

It can be seen that the force of impact is 4 times greater.

I did not consider changing the units of velocity from mph to mps because am comparing the two energies. Even if I convert the velocities to mps, the answer would be same 4 times greater.