Density, Pressure, Upthrust

Question 1

Equation of density

Answer 1

Density = Mass/volume

Question 2

Equation of pressure in solids

Answer 2

Pressure = Perpendicular force/Area

Question 3

Equation of pressure in fluids

Answer 3

P=’rho’gh

Question 4

What is upthrust equal to

Answer 4

Weight of the fluid disposed

Question 5

Equation for upthrust

Answer 5

‘rho’ g volume

Question 6

Archimedes principle

Answer 6

When a body is immersed in a fluid (fully or partially), it experiences a force called upthrust which is equal to the weight of the volume of fluid disposed

Question 7

How to measure volume of a regular cube?

Answer 7

Using a Vernier calliper to find side length → use the volume formulas

Question 8

How to determine volume of an irregular object?

Answer 8

Place the object in water inside a measuring cylinder. The change in volume when the object is fully submerged is equal to the volume of the object

Question 9

Why does an object inside a fluid experiences upthrust?

Answer 9

The pressure at the bottom surface of the object is greater than at its top surface

Question 10

What is true for a floating object?

Answer 10

Upthrust=weight

Question 11

A table tennis ball is held under water and then released, explain what will happen to it (5)

Answer 11

After release weight and upthrust → upthrust is greater → ball accelerates upwards → travels vertically experiencing friction force with water → As it pops out of the water the only force is weight, so it decelerated and falls back → remains still on the water as upthrust = weight