A
An object sits at rest on a horizontal table. Which force acts upward to balance the pull of gravity?
Normal (force)
If you move a box across the floor at a constant speed, how does the applied force compare to the force of friction?
Applied force is equal to friction.
Which of the following determines the strength of the gravitational force between two objects?
Their mass and the distance between them.
Which of the following determines the strength of the gravitational force between two objects?
It increases.
What provides the force that keeps a satellite in orbit around the Earth?
Gravity
Why doesn't a satellite in orbit fall straight down to Earth?
It is moving sideways fast enough.
What would happen to a satellite's orbit if its speed were significantly increased?
It would move into higher orbit.
Which type of friction occurs when you try to push a heavy desk but it doesn't move?
Static friction
A skydiver reaches terminal velocity when...
Air resistance equals their weight
Why is it harder to run through water than through air?
Water resistance is greater than air resistance.
Upthrust is an upward force exerted by a fluid. What determines the strength of upthrust?
The weight or amount of fluid displaced.
If an object is more dense than the fluid it is in, what happens?
It sinks.
Which of these is designed specifically to reduce air resistance?
Parachute
Streamlined Car
Sandpaper
A heavy anchor
Streamlined Car
Which of the following materials is NOT magnetic?
Cobalt
Aluminium
Nickel
Iron
Aluminium
What happens if you break a bar magnet in half?
You get 2 smaller magnets.
In a magnetic field diagram, what do lines that are close together represent?
A strong magnetic force.
What kind of force occurs between two North poles of a magnet?
Repulsion (Repel)
Which of these devices uses the magnetic force to function?
Electric motor
Battery
Solar panel
Lightbulb
Electric motor
How can you increase the magnetic force of an electromagnet?
Increase the current.