Match each example to its type of energy.

solar energy

nuclear energy

fossil fuel energy

wind energy

geothermal energy

a.
energy obtained from a renewable source using solar panels
b.
energy harnessed from the atoms of certain substances
c.
the most common type of energy used today; includes coal, natural gas, oil
d.
energy harnessed by using a turbine and can be expensive initially
e.
energy harnessed from the earth’s natural heating system

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

Who was the first scientist to measure speed as distance over time?