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

Worksheet: Force Pairs and Newton's Third Law of Motion

Q1:

When starting a race, a 55.0-kg-mass sprinter exerts an average force of 635 N backward on the ground for 0.560 s.

What is the sprinter’s speed after the acceleration?

How far does the sprinter move during the acceleration?

Q2:

A 1 1 0 0 . 0 -kg artillery shell is fired from a battleship, and the shell is accelerated at 2 . 4 0 × 1 0 4 m/s2?

What is the magnitude of the net external force exerted on the shell?

What is the magnitude of the force exerted on the ship by the shell’s acceleration?

Q3:

A truck collides with a car and, during the collision, the net force on each vehicle is equal to the force exerted by the other vehicle. The mass of the car is 6 . 0 0 × 1 0 2 kg and the mass of the truck is 2 . 6 3 0 × 1 0 3 kg. The magnitude of the truck’s acceleration is 8.63 m/s2. Find the magnitude of the car’s acceleration.

Q4:

Which of the following is true?

  • AA rocket taking off exerts a force on Earth equal in magnitude to the force Earth exerts on it.
  • BEarth exerts a force due to gravity on your body and your body exerts a smaller force on Earth because your mass is smaller than the mass of Earth.
  • CAn airplane cruising at a constant speed is not affected by gravity.
  • DThe Moon orbits Earth because Earth exerts a force on the Moon and the Moon exerts a force equal in magnitude and opposite in direction on Earth.

Q5:

Which force causes a boat to move forward when someone rows it?

  • AThe frictional force between the boat and the water.
  • BThe frictional force between the oars and the water.
  • CThe force of gravity acting on the oars.
  • DThe force of the oars pushing against the water.

Q6:

What is Newton’s third law of motion also known as?

  • Athe law of force
  • Bthe law of inertia
  • Cthe law of gravitational attraction
  • Dthe law of action-reaction
  • Ethe law of conservation of energy

Q7:

A sports car of mass 550 kg collides with a truck of mass 2 2 0 0 kg, and, during the collision, the net force on each vehicle is the force exerted by the other. The magnitude of the truck’s acceleration is 10 m/s2. What is the magnitude of the sports car’s acceleration?