Gravity
Is gravity a contact or non-contact force?
Non-contact
Is friction a contact or non-contact force?
Contact
What is net force?
The overall force acting on an object after all forces are combined.
A book is sitting on a table. What force acts upwards, opposite to gravity?
Normal force
What subject area does Mrs Backus teach in besides Science?
Humanities
What unit is force measured in?
Newtons (N)
What is an example of useful friction?
Walking, riding a bike, picking something up etc.
10 N right and 4 N left. What is the net force?
6 N right
What force allows a stretched rubber band or spring to return to its original shape?
Elastic force
What is Mrs Backus' favorite colour?
Pink
What is the difference between mass and weight?
Mass is the amount of matter in an object and is measured in kg. Weight is the force of gravity on an object and is measured in N.
Name one factor that affects friction.
Surface type, roughness, material, or how hard the surfaces are pushed together.
If an object is speeding up, are the forces balanced or unbalanced?
Unbalanced, because the object’s motion is changing.
Name a safety feature that reduces the effect of forces in a crash.
Seatbelt, airbag, helmet, crumple zone, padding.
How old is Mrs Backus?
25
A skydiver is falling at terminal velocity. Explain what is happening to the forces.
Gravity pulls down and air resistance acts upwards. The forces are balanced, so the net force is 0 N and the skydiver falls at a constant speed.
Reduce the amount of surface area that affects the air in front of an object. By: Making it narrower, making it smoother etc.
A box is pushed to the right but does not move. What does this tell us about the forces?
They are balanced; another force, like friction, is opposing the push
A student tests whether parachute size affects falling time, what is the independent variable and dependent variable?
IV = parachute size; DV = falling time.
Name one job Mrs Backus had before becoming a teacher.
Swim teacher, OSHC educator, Officeworks print & copy specialist
Why would your weight change on the Moon, but your mass stay the same?
Weight changes because gravity is weaker on the Moon. Mass stays the same because the amount of matter has not changed
A car is driving on an icy road. Why is it harder to stop?
There is less friction between the tyres and the road, so the car takes longer to slow down or stop.
What happens to an object’s motion when the net force is 0 N?
It either stays still or continues moving at a constant speed in the same direction.
A student changes both the ramp height and the surface type in one experiment. Why is this a problem?
It is not a fair test because they changed more than one variable, so they cannot tell which variable affected the result.
What are the names of Mrs Backus' cats?
Ivy & Lily