Chap 2/ Motion
How many significant figures are in the number 320?
2 significant figures
Which has more mass: 5.0 kg of cotton balls or 5.0 kg of pennies?
They have the same mass
Friction turns kinetic energy into this form of energy.
Heat or thermal energy.
Momentum= ___ x ____?
Mass x velocity
He first proposed a heliocentric model of the solar system.
Nicholas Copernicus
How close a measurement is to the accepted value is known as ______.
No spacecraft has gone farther than NASA's Voyager 1. Launched in 1977 to fly by Jupiter and Saturn, Voyager 1 crossed into interstellar space in August 2012 and continues to collect data. How much force is needed to keep this probe moving through interstellar space?
No force is needed! It keeps moving by it's own inertia.
What is the first step in any energy trail? Include both the place and form.
The sun as nuclear energy.
What are the units for momentum?
kg x m/s
What is the speed of light?
3.00 x 10^8 m/s or 300,000,000 m/s.
The rate at which velocity changes
Acceleration
According to Newton, in order for you to make a tight turn, what must be present?
a force
A cliff diver has 5000 J of gravitational potential energy as he stands on a cliff. If he dives off the cliff, how much kinetic energy will he have when he is exactly halfway between the cliff and the water? Assume there is no air resistance.
2500 J.
Which has more momentum: a 50.0 kg person running at 2.0 m/s or a 40.0 kg dog running at 3.0 m/s?
The dog
This variable can affect the results of an experiment without the researchers being aware of it.
the lurking variable.
First stated that the planets' orbits were ellipses.
Johannes Kepler
A pancake is thrown against a wall. What are the action and reaction forces involved in this interaction (between the pancake and wall)?
The pancake hits the wall and the wall hits the pancake back with the same amount of force (and in the opposite direction).
Give a place/form that energy would reside in on its way from the sun to a galloping horse? (Don't choose the sun or the horse).
As electromagnetic waves in space
As chemical potential energy in a plant
In which type of collision are BOTH the kinetic energy and the momentum conserved?
elastic collision
According to Einstein, a gravitational field can affect these two things.
Mass and electromagnetic waves.
Mrs. G travels at an average speed of 15.0 m/s to pick up her daughter from school. If the school is 4800 m away, how long will it take her to get there?
320 seconds (or 5.3 minutes)
How much force is needed to accelerate a 0.177 kg softball at 20.0 m/s^2?
3.54 N
A cliff diver has a mass of 70.0 kg and stands on a 15.0 m high cliff. How much gravitational potential energy does he have?
10,300 J.
A basketball (mass 0.567 kg) rolling at 5.00 m/s runs into a softball (mass 0.177 kg) which is at rest. After the collision, the basketball is moving at a speed of 2.62 m/s. What is the speed of the softball?
7.62 m/s.
He observed a nova and the conjunction of Jupiter and Saturn, both which supported Copernicus's heliocentric view of the solar system.