Topic 1.2: Forces and Momentum Questions

State what is meant by the static friction force acting on an object.

State what is meant by the terminal velocity of an object falling through a fluid.

A 2.5 kg block sliding on a frictionless surface speeds up from 3.0 m s⁻¹ to 11 m s⁻¹ along a straight line.

Calculate the impulse delivered to the block.

A 0.45 kg ball experiences a single net force of 6.0 N.

Calculate the magnitude of its acceleration.

A single force of 200 N acts on a trolley at 52° above the horizontal.

Calculate the horizontal and vertical components of this force.

(cos 52° = 0.62, sin 52° = 0.79)

State what is meant by an object being in translational equilibrium.

A cork floats at rest, partly submerged, on the surface of still water.

Identify the two forces acting on the cork and state the relationship between their magnitudes.

State what is meant by the momentum of an object, and explain why momentum is a vector quantity.

State Newton's first law of motion.

State Archimedes' principle.

A solid brass cylinder of volume 4.0 × 10⁻⁴ m³ is fully submerged in water of density 1.0 × 10³ kg m⁻³ (g = 9.8 N kg⁻¹).

Calculate the buoyancy force on the cylinder.

A 0.45 kg ball travelling at 14 m s⁻¹ is caught by a fielder and brought to rest in 0.060 s.

Determine the magnitude of the average force the fielder's hands exert on the ball.

State the condition that must be met for the total momentum of a system of objects to be conserved during a collision.

A satellite moves in a circular orbit around a planet at a constant speed.

State the direction of the net force acting on the satellite, and state why the satellite is accelerating even though its speed does not change.

Explain why a hot-air balloon rises even though the hot air inside it still has mass and weight.

Identical blocks are placed on two horizontal surfaces.

On surface A the coefficient of static friction is 0.50; on surface B it is 0.20.

The normal force on each block is 29 N.

A 3.0 kg block is driven up a smooth vertical wall by a constant force of 45 N pushing straight up.

Taking g = 9.8 m s⁻², determine the block's acceleration up the wall.

An iceberg of volume 1.3 × 10⁶ m³ floats in seawater.

Ice has density 9.2 × 10² kg m⁻³ and seawater 1.03 × 10³ kg m⁻³ (g = 9.8 N kg⁻¹).

Show that the mass of the iceberg is about 1.2 × 10⁹ kg.

In an experiment a student measures the friction force on a sliding block as 6.0 N when the normal force is 24 N.

Two ice-hockey pucks slide head-on toward each other on frictionless ice.

Puck A has mass 0.16 kg and velocity +3.0 m s⁻¹; puck B has mass 0.16 kg and velocity −1.0 m s⁻¹.

They collide and stick together.

Calculate the velocity of the combined pucks after the collision.