kinetic calculation

Kinetic energy is the energy of motion. How could you determine how much kinetic energy an object has?

• by finding its height and width

• by finding its speed and direction

• by finding its position and form

• by finding its mass and speed

The diagram below shows two boulders that are rolling down a mountain slope.

The mass of one boulder is 1,000 kilograms, and the mass of the other boulder is 50 kilograms. If both of the boulders are moving at the same speed, which of the following statements is true when both reach point A before touching the ground?

• The 1,000-kg boulder has more kinetic energy than the 50-kg boulder.

• The 50-kg boulder has more kinetic energy than the 1,000-kg boulder.

• Neither boulder has any kinetic energy.

• The boulders have the same kinetic energy.

Two cars that are identical except for their color are traveling on the same road.

The red car is traveling at a speed of 78 km/hr, and the blue car is traveling at a speed of 106 km/hr. Which of the following statements is true?

• Neither car has any kinetic energy.

• The red car has more kinetic energy than the blue car.

• The blue car has more kinetic energy than the red car.

• The cars have the same kinetic energy.

An explosion of gas from a Hawaiian volcano blows a rock into the sky. the rock has 2000J of kinetic energy. What was its mass if the rock had a velocity of 20m/s

• 200Kg
• 20,000Kg
• 10Kg
• 200Kg

An 8kg dog chases a cat. if the dog has 400J of kinetic energy. What is the speed of the dog?

• 10 m/s
• 5 m/s
• 1 m/s
• 100 m/s