# Worksheet: Inertia and Newton's First Law of Motion

In this worksheet, we will practice calculating the unknown forces acting on an object so that it remains still or moves at a constant velocity.

Q1:

Three forces act on a particle, which moves with constant velocity . Two of the forces are and . Find the third force, .

• A N
• B N
• C N
• D N
• E N

Q2:

Assume that east corresponds to positive displacement along the -axis and that north corresponds to positive displacement along the -axis.

Find the net force in component form.

• A
• B
• C
• D
• E

At what angle north of east is the net force directed?

Find the direction of the net force.

If Maher and Hanan’s housemates, Omar and Nehal, disagree with the move and want to prevent its relocation, with what combined force should they push so that the couch does not move?

• A N
• B N
• C N
• D N
• E N

Q3:

Two forces and act on an object. What force must be added to and to produce a net force of zero?

• A N
• B N
• C N
• D N
• E N

Q4:

A force is applied to accelerate an object on a smooth icy surface. When the force stops, which of the following will be true? (Assume that friction is zero.)

• AThe object’s acceleration continues to increase at a constant rate.
• BThe object’s speed becomes zero.
• CThe object accelerates, but in the opposite direction.
• DThe object’s acceleration becomes zero.

Q5:

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

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