Question 1
The figure below shows a micrometer screw gauge used by a student to measure the thickness of a wire. If it has a zero error of +0.08mm, determine the actual thickness of the wire
Answer
Sleeve scale reading = 5.50mm
Thimble scale reading = 30 x 0.01mm = 0.30mm
Micrometer screw gauge reading = 5.50mm + 0.30mm = 5.80mm
Actual thickness of the wire = 5.80mm + 0.08mm = 5.88mm
Thimble scale reading = 30 x 0.01mm = 0.30mm
Micrometer screw gauge reading = 5.50mm + 0.30mm = 5.80mm
Actual thickness of the wire = 5.80mm + 0.08mm = 5.88mm
Question 2
A paratrooper flexes his legs when he lands. Explain
Answer
Bright specks are seen to be moving in random motion.The bright specks are smoke particles which are bombarded by the invisible air molecules which are in continuous state of random motion.
Question 3
The diagrams below show two glass tubes of different diameters dipped in water
Explain why h2 is less than h1.
Answer
Since tube 2 is wider, the adhesive force between water molecules and the glass tube 2 is weaker/lower compared to the adhesive force between water molecules and glass tube 1 hence h2 is less than h1
Question 4
State a reason why a burn from steam at 1000C is more severe than a burn from boiling water at the same temperature
Answer
Steam at 1000C has more energy because it has latent heat of vaporization as opposed to water at 1000C which does not poses latent heat of vaporization
Question 5
The figure below shows the instrument used to measure pressure
a) Name the instrument
b) What would be observed if the test tube is tilted assuming the instrument is functioning normally
Answer
a) Mercury barometer
b) X will increase Mercury fill the tube
b) X will increase Mercury fill the tube