AS 4 Force, Density, and Pressure

What's the magical formula for finding upthrust?

• upthrust = weight of the fluid displaced by the object

• upthrust force = density of the object

• upthrust = mass of the object

• upthrust = volume of the object

Answer explanation

The formula for calculating buoyant force is Buoyant force = weight of the fluid displaced by the object. This formula is derived from Archimedes' principle.

What happens to the pressure in a fluid as we go deeper and the fluid becomes denser?

• The pressure remains the same regardless of the depth and density.

• The pressure increases as we go deeper and the fluid becomes denser.

• The pressure decreases as we go deeper and the fluid becomes denser.

What is the density of a substance if its mass is 500g and its volume is 250cm^3?

• 250 g/cm^3

• 2 g/cm^3

• 0.002 g/cm^3

• 1000 g/cm^3

Explain the concept of torque and how it is related to force and distance.

• Torque is the measure of the force that can cause an object to move in a straight line

• Torque is the measure of the force that can cause an object to rotate around an axis. It is related to force and distance through the equation Torque = Force x Distance.

• Torque is only related to distance and not force

What role does friction play in the movement of an object on an inclined plane?

• Friction slows down the object's movement

• Friction causes the object to move in the opposite direction

• Friction speeds up the object's movement

• Friction has no effect on the object's movement

What is the reaction force on an object placed on a horizontal surface if the gravitational force acting on the object is 100N?

• 50N

• 200N

• 100N

• 0N

A cardboard with weight 0.15 N is held at point P.

How will the cardboard rotate?

• Clockwise

• Anticlockwise

• No rotation, because it is in equilibrium.

What force of friction is needed to keep a 5kg block stationary on a 30-degree inclined plane?

• 3 N

• 25 N

• 43 N

• 49 N

A box slides down a rough plane.

Draw and label all forces on the box.

An airplane takes off at steady speed of 250 km/h at an angle of 10° and experiences the forces shown.

It is said to be in equilibrium.

• True

• False