Speed, Distance and Time
A car travels at a speed of 60 km/h for 2 hours. How far does it travel?
120 km
A soccer ball is sitting still on the field. According to Newton's First Law, what will happen to the ball if no forces act on it?
It will remain at rest.
What is Net Force
Total forces acting on a object.
what is energy efficiency?
It is the measure of how much input energy is converted into useful output energy instead of being wasted.
Which metro stations are older and which metro stations are newer?
The Hills District metro stations between Tallawong and Chatswood are older.
The City and West metro stations between Chatswood and Bankstown are newer.
Train A passes a passenger in Train B in 6 seconds. How long does Train B take to pass?
6 seconds. Relative speed and distance between the passenger and the opposite train are exactly identical for both.
What is the formula for Newton's Second Law
f=ma
Whats a balanced force
Two individual forces acting on a object with equal strength.
What is the main formula for efficiency?
Efficiency equals useful output energy divided by total input energy, often multiplied by 100 to make a percentage.
How is the Sydney metro driven?
Driverless trains (GoA4 Technology).
Convert km/h into m/s
Divide by 3.6
Why do passengers lurch forward when a car suddenly brakes?
Because their bodies want to continue moving forward due to inertia (Newton's First Law).
Whats a unbalanced force.
Two individual forces acting on a object with different amounts of strength.
A motor has a total energy input of 2,000 joules and does 1,200 joules of useful work. What is its energy efficiency?
60%
What is the Metro’s Top Speed?
110 km/h during testing or 100km/h during normal services
Which car is travelling faster if the speed of car A is 10m/s and car B is 35km/h?
Car A (36km/h)
Two shopping trolleys are pushed with the same force. One trolley is empty and the other is full. Which trolley will accelerate more, and why?
The empty trolley will accelerate more because it has less mass, so the same force produces a greater acceleration.
What is the net force of an object if two equal forces push in opposite directions
0N, becuase they balance out.
A microwave with a total power input of 900 watts has an efficiency of 70% (0.70). What is its useful power output?
630 watts
How many breaking systems does the Sydney metro have?
The Sydney metro has 4 breaking systems
Two trains start 300km apart. They travel towards each other. Train A travels at 40km/h and train B travels at 60km/h. How many hours until they meet?
3 hours
A rocket launches into space by pushing hot gases downward. Which Newton's Law explains this, and what is the action-reaction pair?
Newton's Third Law.
An object is pulled with 15N to the north and 10N to the south. What is the net force?
5N North.
An incandescent light bulb consumes 200 joules of electrical energy per second and emits 25 joules of useful light energy per second. What is its energy efficiency percentage, and how much energy is wasted
12.5%, 175 joules per second
What forces are acting on an elevator (metro stations)?
Gravity, Tension, normal force and Friction and Drag