Explaining the Magic of Physics in Everyday Life - Assignment Example

Explaining the Magic of Physics in Everyday Life College Affiliation Department of Physics, HKU How Things Works (PHYS1055 Revealing the Magic in Everyday Life (PHYS0612)Question 1Description of the motion of the object in reversed play Initially, when the film was playing forward, the object was viewed to be accelerating downwards. This acceleration is due to gravity which usually is 9.8m/s as depicted in the film. However, when Peter runs the film backwards, the motion of the object shall be decelerating as it as it is occurring in the opposite direction back to its starting point, the point at which its velocity was zero.

In this case, I agree with Peter. The reason why I agree with Peter is because in reality the object was accelerating downward in the forward play, when played backwards, the object will still seem to be accelerating downwards. This is because natural motion seems similar when time is run backwards as the laws of motion are symmetric in relation to reversal of time. In Peter’s case, time was run backwards in the film. The equations required to explain motion under consistent acceleration are similar as those used to explain the motion of an object in a film playing in reverse.

Question 2 The tension on the pants would not be changed at all. Tension is as a result of two forces acting in opposite directions. It is a tensor. It can be assumed that in the Levi Strauss trademark when the two horses are pulling the pants each horse exerts a force of 10,000N, hence, each horse is exerting the same amount of force on the pants which results in a deadlock. If one horse was used to pull the pants while attached to a tree trunk, the tree trunk would also exert an equal amount of force because for every action there is a reaction.

Hence, the tension in the pants would not be reduced by one half. For if it was to be reduced by one half, it means the horse would pull away the pants from the log.Question 3 Air bubbles rise steadily under water. This is because air is less dense than water therefore the force of gravity acting on the bubble will be less causing the air bubble to float. The air bubble will increase its size to the surface of the water since it expands with decreasing pressure. As the volume of the bubbles increases, they will become less dense than water because of the lowered pressure.

Question 4 The iron disk is a metal which is a solid. It is well known that when solids are heated, they expand. Molecules in the iron disk vibrate about their mean position upon heating. As the heating is increased, the vibration of the molecules in the iron disk about their mean position increases. The molecules in the iron disk will move farther from each other as the energy from heating increases. This means that the iron disk shall expand. The diameter of the hole will expand along with the expanding iron disk, meaning it shall increase.

This is because the hole in the iron disk acts in a similar manner as the circle of the same component which is iron. If it is assumed that the molecules of the iron disk lining the outside of the hole expand inwards hence reducing the diameter of the hole, they will have to face resistance in which case this beats logic and the laws of thermodynamics. This means they expand to the outside which increases the diameter of the hole as the circumference of the hole gets larger along with the expanding iron disk.