Phys101
Term:113
Online HW-Ch14-Lec02
Q1:
Barometers and open-tube manometers are two instruments that are used to measure
pressure:
A. Both measure gauge pressure
B. Both measure absolute pressure
C. Barometers measure gauge pressure and manometers absolute pressure
D. Barometers measure absolute pressure and manometers measure gauge
pressure
E. Both measure an average of the absolute and gauge pressures
Ans:
D
Q2:
The mass of a block of aluminum is 25.0 g. What will be the tension in a
string that suspends the block when the block is totally submerged in water?
The density of aluminum is 2700 kg/m3
Ans:
Q3:
T = mg − FB = mAl g − ρwVAl g = ρAl VAl g − ρw VAR g
mAl
= vAl g (ρAl − ρw ) =
g (ρAl − ρw )
ρAl
= 0.154 N
In a hydraulic press such as the one shown in Figure, the large piston has
cross-sectional area A 1 = 200 cm2 and the small piston has a cross sectional
Area A 2 = 50 cm2. If a force of 250 N is applied to the small piston, find the
force F1 on the large piston?
Ans:
F1
A1
F
A
= A2 ⇒ F1 = �A1 � F2 = 10 kN
2
KFUPM-Physics Department
2
1