Friction
What is a force?
A push or a pull.
What is friction?
A force that opposes motion between surfaces.
What is the variable you purposefully change called?
Independent Variable
Which planet is the biggest
Jupiter
Name one method used to separate mixtures.
Any of the following; Filtration, evaporation, sieving, decanting, crystallisation
Name one contact force and one non-contact force.
Contact - applied force/friction/normal force
Non-Contact - gravity/magnetic force.
Give one example where friction is useful.
Walking, tyres gripping the road, brakes, holding objects
What is the variable you measure called?
Dependent Variable
What is the basic unit of life?
Cells
What are the 7 main levels of classification
Kingdom, Phylum, Class, Order, Family, Genus, Species
What happens to an object when the forces acting on it are balanced?
it stays still or continues moving at constant velocity
Why does a rough surface usually produce more friction than a smooth surface?
Rough surfaces have more bumps/irregularities that interact and resist movement.
Why should you only change one variable in a fair test?
So you can determine whether the variable you changed caused the result.
What gas do plants take in during photosynthesis?
Carbon Dioxide (CO2)
Which separation technique would you use to separate sand from water?
Filtration.
A box is pushed right with 20 N and left with 12 N. What is the resultant force?
8 N to the right.
Explain how friction affects the movement of a bicycle.
Friction between tyres and the ground provides grip; brakes use friction to slow the bicycle
A student tests how ramp height affects the distance a toy car travels. Identify the independent and dependent variables.
Independent = ramp height
Dependent = distance travelled.
What is the largest organ in the human body?
Skin
Explain the difference between filtration and evaporation.
Filtration separates an insoluble solid from a liquid using a filter; evaporation removes a liquid and leaves the dissolved solid behind.
A car is travelling at a constant speed in a straight line. What does this tell you about the forces acting on it?
The forces are balanced/resultant force is zero.
A student wants a toy car to travel further along the floor. Give one way they could reduce friction and explain why it would work
smoother surface, lubricate moving parts, use wheels/bearings. Less friction means less force opposes the car’s movement.
A student changes the ramp height, car mass and floor surface all at once. Explain why this is not a fair test and how to improve it.
Too many variables are changed, so you cannot tell which one caused the result. Change only one variable and keep the others controlled.
What is the name of the process where a solid changes directly into a gas?
Sublimation
An organism is classified as Canis lupus. What do the two words in its scientific name represent?
Canis = genus; lupus = species