Effects of Forces on Motion of a Body

# Effects of Forces on Motion of a Body problem 22

Determine whether the description of Newton's first or third laws applies in the given cases.

• A car drives uniformly on a level road. It is acted upon by the force of the engine and, conversely, by the same force of air resistance.

• The force of water resistance inhibits the navigation of the ship, and the ship acts with force on the water to cause waves. Both forces are equal and opposite.

• Push a trolley on a flat surface with the force of your hands so that it moves uniformly.

• A locomotive acts with force F on the train carriages and accelerates them. The wagons operate with the same opposite force on the locomotive.

• A body hangs on a string. The sum of the force on the string and the weight of the body is zero, so the body is at rest.

• A body hangs on a string. With its weight it acts on the string vertically downwards, and the string with the equal and opposite force on the body.

material editor: Gabriel Amakhabi