Q1. Weight is the effect of gravity on an object's mass. Therefore, if mass remains constant, then only gravity will affect mass. In comparison to Earth, the moon has less mass than the Earth. Thus, your weight on the moon is a lot less in comparison to when on the Earth as there is less gravitational effect on your gravity. Q2. Due to inertia, objects will remain in motion unless an outer force acts upon them. Thus, when the bus stops the passengers inside are still going in a forwards motion. This causes them to move forwards until the force is balanced. Q3. According to Newton's 1st Law of Motion, stationary objects remain stationary unless an external unbalanced force acts upon them. In this scenario, although the car is accelerating, I am still a stationary object, until the car's motion acts upon me. This causes me to appear to move backwards, however I am gaining momentum as my motion balances with the cars motion, from a point of stationary movement to an equal motion inline with the car. Q4. 1. Use smoother surfaces 2. Reduce contact between two surfaces 3. Reduce pressure/weight on the surface 4. Use lubrication.
1. Find the average speed of a car which travels 10 kilometres in 5 minutes.
Average speed is 33.3 m/s.
2. An aeroplane travels 35,000 metres in 6 minutes. Find the average velocity of the plane if it is flying from east to west.
97.2 m/s West.
3. How far does an object move in 3 seconds at an average speed of 26 ms-1?
78 metres.
4. A yacht has a velocity of 8 ms-1 south. How long will it take to travel 10 km?
1250 seconds or 20.83 minutes.
5. A pool ball travels 2 metres east in 0.5 seconds, then 2 metres west in 0.25 seconds.
a. What is the pool ball’s displacement?
0m
b. What is the average velocity of the ball?
0 m/s
c. What is its average speed?
5.33 m/s
Q10. a) 25km North b) 125/9 m/s c) 0.7 hours.
