Question 1
Figure 1, shows a Vernier caliper of zero error 0.02 cm being used for measuring the diameter of a cylindrical container of height 10 cm. The scale reading of the Vernier is as shown alongside.
a. Determine the diameter of the container
b. Estimate the volume of a liquid which can completely fill the container
Answer
a. reading = 3.7 + 0.02 = 3.72cm ;
actual diameter = 3.72 - 0.02 = 3.70cm ;
b.
actual diameter = 3.72 - 0.02 = 3.70cm ;
b.
Question 2
State one factor that affects the turning effect of a force on a body
Answer
- Magnitude of the force
- Perpendicular distance between pivot and line of action of force
- Perpendicular distance between pivot and line of action of force
Question 3
Figure 2 shows some air trapped by mercury in a glass tube. The tube is inverted in a dish containing mercury.
Given that the atmospheric pressure is 760 mmHg and the height of mercury column in the tube is 600 mm, determine the pressure of the air trapped in the tube in mmHg.
Answer
atm.pressure = liquid pressure + air pressure
760 = 600 + air pressure
Therefore air pressure = 760 - 600 = 160mmHg
760 = 600 + air pressure
Therefore air pressure = 760 - 600 = 160mmHg
Question 4
Figure 3 shows drops of mercury and water on a glass surface, Explain the difference in the shapes of the drops.
Answer
Cohesive force among mercury molecules is stronger than adhesive force between mercury and glass molecules; in water, adhesive force between water and glass molecules is stronger than cohesive force between water molecules.
Question 5
A ball is thrown from the top of a cliff 20m high with a horizontal velocity of 10ms-1. Calculate the distance from the foot of the cliff to where the ball strikes the ground.
Answer