Question
An object is at rest on a horizontal surface.
Which equation is used to calculate the pressure that the object exerts?
A. $\frac{\text { mass of the object }}{\text { area of contact }}$
B. $\frac{\text { weight of the object }}{\text { area of contact }}$
C. ${\text { weight of the object }}$ $\times $ ${\text { area of contact }}$
D. ${\text { weight of the object }}$ $\times $ ${\text { area of contact }}$
Answer/Explanation
Ans:B
Question
A drawing pin (thumb tack) has a sharp point at one end and a flat surface at the other end.
The pin is pushed into a wooden board.
How do the pressure and the force at the sharp point compare with the pressure and the force on the flat surface?
Answer/Explanation
Ans:C
Question
An object is $20 \mathrm{~cm}$ below the surface of a liquid. The density of the liquid is $1200 \mathrm{~kg} / \mathrm{m}^3$.
What is the pressure on the object due to the liquid?
A $600 \mathrm{~Pa}$
B $2400 \mathrm{~Pa}$
C $60000 \mathrm{~Pa}$
D $240000 \mathrm{~Pa}$
Answer/Explanation
Ans:B
Question
The diagram shows a manometer connected to a gas supply.
What is the pressure of the gas supply?
A 100 mm Hg above atmospheric pressure
B 100 mm Hg below atmospheric pressure
C 200 mm Hg above atmospheric pressure
D 200 mm Hg below atmospheric pressure
Answer/Explanation
Ans: C
Question
The diagram shows a box of dimensions 6.0 cm ×8.0 cm ×4.0 cm.
The box rests on a flat horizontal surface.
On which face must the box rest in order to exert the least pressure?
A face X
B face Y
C face Z
D The pressure is the same for all the
Answer/Explanation
Ans: A