Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.

Please verify your account before proceeding.

In this lesson, we will learn how to calculate the kinetic energy of an object moving relative to an observer given its mass and velocity.

Q1:

An 8.0-g bullet has a speed of 800 m/s.

What is its kinetic energy?

What is its kinetic energy if the speed is halved?

Q2:

How fast must a 3 0 0 0 -kg elephant move to have the same kinetic energy as a 65.0-kg sprinter running at 10.0 m/s?

Q3:

You are launching a 2.0 kg potato out of a potato cannon. The cannon is 1.5 m long and is aimed 30 degrees above the horizontal. It exerts a 50 N force on the potato. What is the kinetic energy of the potato as it leaves the muzzle of the potato cannon?

Q4:

An aircraft carrier has a mass of 7 8 5 6 0 tons and moves at a speed of 24 nautical miles per hour. What is the kinetic energy of the aircraft carrier?

Q5:

An automobile of mass 2 . 0 0 × 1 0 3 kg has a velocity of 1 . 0 0 × 1 0 2 km/h, a runner of mass 80 kg has a velocity of 10.0 m/s, and an electron has a velocity of 2 . 0 × 1 0 7 m/s.

What is the kinetic energy of the automobile?

What is the kinetic energy of the runner?

What is the kinetic energy of the electron?

Q6:

An object with a mass of 3.3 kg has four times the kinetic energy of an object with a mass of 7.4 kg. What is the ratio of the speed of the 3.3-kg-mass object to the speed of the 7.4-kg-mass object?

Q7:

A spring has a mass of 10.0 g, uniformly distributed along its length. The left end of the spring is fixed. The right end of the spring is moving in the 𝑥 -direction at 0.125 m/s and the right end of the spring is at the equilibrium position 𝑥 = 0 . 0 0 0 m . What is the kinetic energy of the spring?

Q8:

How many times greater is the kinetic energy of a 72.6-kg-mass astronaut with a velocity of 2 1 2 0 0 km/h than the kinetic energy of a 2 2 3 5 0 -kg-mass truck with a velocity of 105 km/h?

Q9:

A child is pulling two red wagons, with the second one tied to the first by a (nonstretching) rope. Each wagon has a mass of 5.0 kg. If the child exerts a force of 40 N for 6.0 m, how much has the kinetic energy of the two-wagon system changed?

Q10:

If wind is blowing horizontally toward a car at an angle of 30 degrees from the direction of travel, the kinetic energy of the car will . If the wind is blowing at a car at 135 degrees from the direction of travel, the kinetic energy of the car will .

Q11:

A bullet from a 0.22LR-caliber cartridge has a mass of 2.60 g and a muzzle velocity of 335 m/s. It is fired and penetrates a door of 1-inch thick (2.54 cm) pine board that generates a stopping force of 120 N. How fast would the bullet be traveling after it penetrated through the door?

Q12:

What is the kinetic energy of an athlete of mass 80 kg who is running at 10.0 m/s?

Q13:

The Chicxulub crater in Yucatan, one of the largest existing impact craters on Earth, was created by an asteroid that has been modeled as impacting the Earth traveling at 22 km/s, dissipating 4 . 2 × 1 0 2 3 J of energy. What is the minimum mass of the asteroid necessary to have done this?

Q14:

What is the kinetic energy of a neutron moving at a speed of 2.2 km/s?

Q15:

A basketball player throws a ball of mass 624 g and it moves a distance of 15.0 m in 2.000 s. What is the ball’s translational kinetic energy while it is moving?

Don’t have an account? Sign Up