Graphs & Calculations
Motion & Energy
Forces
Fluid Principles
Astronomy
100
On a speed vs. time graph, the slope of the graph represents...
The acceleration of the object
100
A place or object used for comparison to determine if something is in motion is called what?
A reference point
100
Which of the following is an example of increasing friction intentionally? (a) waxing skis (b) throwing sand on an icy driveway (c) adding grease to gears on a bike (d) oiling a squeaky door
(b) throwing sand on an icy driveway
100
An object has a density of .75 g/mL. Will it float or sink in water?
It will float
100
What is a light year?
The distance that light travels in a year
200
A skydiver with a mass of 70 kg accelerates to Earth at a rate of 9.8 m/s/s due to gravity. What is the force on the skydiver?
686 Newtons
200
Which of the following has kinetic energy? (a)a rock poised (getting ready ) to fall (b)an archer’s bow that is drawn back (c)a rolling bowling ball (d)a car waiting at a red light
(c)a rolling bowling ball
200
Why don't action-reaction forces cancel out?
They are acting on different objects
200
A ship is floating in water. It will stay afloat as long as the buoyant force is _______ to the weight of the boat.
Equal to (or more than)
200
Why does Earth have seasons?
The Earth's axis is tilted, and as it moves around the sun different parts of the Earth receive different amounts of direct sunlight.
300
The rise of a line on a distance-time graph is 800 km and the run is 50 hours. What is the speed of the object represented by this graph?
16 km/hr
300
Calculate the speed of a truck that covers 175 km in 3 hours.
s = d/t = 175/3 = 58.33 km/hr
300
A person travelling in a car that stops suddenly keeps moving forward due to...?
Inertia (resistance to a change in motion)
300
How does a submarine control whether it floats or sinks?
It can allow seawater to flow into empty tanks, which increases the mass (and density) and makes the submarine sink. To float, the submarine pumps water out which decreases the mass (and density).
300
What do all of the inner planets have in common?
Small, Rocky Composition, Slow Rotation, Short Revolution, Few Moons, Close to the Sun,
400
What kind of line on a distance-versus-time graph indicates that the object is accelerating?
A curved line
400
Clifford is riding a skateboard and has an acceleration of -2 m/s/s. What do you know about Clifford’s motion?
Clifford is slowing down
400
According to Newton’s third law of motion, when a hammer strikes and exerts force on a nail, the nail does what?
The nail exerts an equal force in the opposite direction back on the hammer.
400
How does a spray-paint can work?
Air is pushed quickly over the top of the paint tube, which creates an area of low pressure. Objects are always pushed from high pressure to low pressure, so paint is pushed up the tube into the moving air and sprays out.
400
Draw the arrangement of the Earth, Moon, and Sun during a lunar eclipse.
Sun ---- Earth ---- Moon
500
Calculate the acceleration of a cheetah who was sleeping and then spots an antelope in the distance and reaches a speed of 80 km/hr in 10 seconds.
8 km/hr/s
500
A ball is thrown straight up in the air and is allowed to fall all the way to the ground. Where does it have the greatest potential energy? Where does it have the greatest kinetic energy?
Greatest PE is wherever height is the greatest (at its Apex), greatest KE is wherever speed is the greatest (right before it hits the ground)
500
How does a rocket lift off into space (what law is this based on)? What has to be true about the forces involved in order for the rocket to actually lift off?
A rocket burns fuel, which pushes down on the air below the rocket. According to Newton's 3rd Law, the air pushes up on the rocket with an equal amount of force (LIFT or THRUST). In order for the rocket to reach space, the upward lift must be stronger than the downward pull of gravity.
500
When you inhale, why does air flow into your lungs? Why is it harder to breathe in the mountains?
Your diaphragm lowers, which increases the area of your lungs. P=F/a, so the increase in area decreases the pressure in your lungs. Objects are pushed from high pressure to low pressure, so air flows into your lungs. This is harder in the mountains because as elevation increases, air pressure decreases, and it is harder to get your lungs to a lower pressure than the surrounding air.
500
What conditions are required for humans to survive on another planet?
Suitable temperature, liquid water, breathable atmosphere (The Goldilocks conditions)
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