Question 1
The figure below shows a cylinder with water and ten lead pellets each of volume 1.8cm3
Indicate on the diagram the level of water if the pellets are removed
Answer
Question 2
The diagram below shows two clear glass tubes containing water and mercury
Explain the shapes of the surface of each of the liquids inside the tube.
Answer
Force of adhesion is stronger than force of cohsion in tube (a) containing water causing it curve upwards in (b) The force of cohesion is greater than the force of adhesion causing the mercury surface to curve upwards
Question 3
The figure below shows a U-tube manometer containing a liquid L, one end in connected to a gas tap
Given that the atmospheric pressure is 1.0 x 105 pa, determine the pressure of the gas (density of liquid L is 900kg/m3.
(Take g = 10N/kg)
Answer
gas pressure = Pa + hpg
= 1.0 x 105 pa + 900 x10 x 0.06
= 100000 + 540
= 100540 pa
= 1.0 x 105 pa + 900 x10 x 0.06
= 100000 + 540
= 100540 pa
Question 4
4. The figure below shows a liquid in a long cylindrical tube closed at one end with a cork. The cork is tight fitting but movable. The system is in equilibrium.
(i) State two observations that would be made when the tube is gently heated uniformly.
(ii) Explain your observation above.
Answer
(i) The cork moves to the left and the tube tilts to the left in anticlockwise direction
(ii) Liquid expand when heated pushing the cork to the left. This shift the centre to the left giving the tube an anticlockwise motion.
Question 5
Explain why in cold weather the metal blade of a knife feels colder that the wooden handle
Answer
Metals are good conductors of heat thus conducts heat from the hand to the metal blade and gives a cold sensation. While wood is a poor conductor of heat.