Question

Which has greater kinetic energy, a car traveling at 30 km/HR or a car of half the mass traveling at 60 km/HR? a. The 60 km/HR carb. The 30 km/HR carc. Both have the same kinetic energyd. More information is needed about the distance traveled

Answer 1

Which of the following objects have kinetic energy? Check all that apply.

a book lying on a shelf

✔a book inside a moving vehicle

✔a running cat

an unmoving rock in the middle of the road

a picture hanging on a wall

✔a falling meteorite

Two cars, car A and car B, have equal mass. Which car has the greater kinetic energy if both cars have the same velocity?

✔ Both cars have equal kinetic energy.

Which has more kinetic energy, a small sports car traveling at 30 km/hr or a large tractor-trailer traveling at 75 km/hr?

✔ The tractor-trailer has more kinetic energy.

Answer 2

a.The 60 km/HR car

Step-by-step explanation:

Kinetic Energy: This can be defined as the energy of a body due to motion. The S.I unit of kinetic energy is Joules (J).

It can be expressed mathematically as

Ek = 1/2mv²......................... Equation 1

Where Ek = kinetic energy, m = mass, v = velocity.

(i) A car travelling at 30 km/hr, with a mass of m,

Ek = 1/2(m)(30)²

Ek = 450m J.

(ii) A car travelling at 60 km/hr, with a mass of m/2

Ek = 1/2(m/2)(60)²

Ek = 900m J.

Thus , the car travelling at 60 km/hr at half mass has a greater kinetic energy to the car traveling at 30 km/hr at full mass.

The right option is a.The 60 km/HR car