Physics Answers

(a) Compute the energy released from a pair production reaction. [2 marks]

(b) Using the line of stability curve, briefly explain why Helium 6

2He is unstable and would

eventually decay into 6

3Li. Indicate the corresponding decay reaction equation. [4 marks]

(c) The Figure bellow represents a typical X-ray spectrum from a tungsten target. Explain the

behaviour of the observed spectrum as far the mechanism of X-ray production is concerned.

[4 marks] .

When the speed of a fluid flowing in a pipe increases, what happens to the internal

pressure in the fluid?

Why is it that an aneroid barometer is able to measure altitude as well as atmospheric

pressure?

When you drink liquid through a straw, it is more accurate to say that the liquid is

pushed up the straw rather than sucked up the straw. What exactly is pushing? Explain.

What is the mass of a cubic meter of air at 20oC at sea level?

How does the density of gases at different elevations in the atmosphere differ from the

density of liquids at different depths?

What is the buoyant force that acts on a 100-ton ship? (To make things simple, give your

answer in tons.)

If the buoyant force on a submerged object is less than the weight of the object, how do

the densities of the object and water compare?

A 12kg mass is placed on a 30° frictionless inclined plane attached to a pulley connected to a hanging mass of 5kg. What is the acceleration of the system?

Please check the document for question: https://docs.google.com/document/d/1v7fAIfShqOjC-7pKGqlwPMHSbH-vx0TDznvnKmFtre4/edit?usp=sharing

Ans: 90 N to the right