Rock Layers & Relative Age
A scientist examines an undisturbed stack of rock layers. Which layer would have formed first?
The bottom layer.
When describing an object's position, what must it be compared to?
A reference point.
A soccer ball is rolling across a field. What type of energy does it have because it is moving?
Kinetic energy.
Magnetic and electric forces can act without touching an object. What type of forces are these?
Non contact forces.
What do we call the number of wave cycles that occur each second?
Frequency.
Why can scientists compare the ages of two rock layers even if they do not know the exact age of either layer?
They can determine their relative ages (age relative to the other rock layer).
A runner travels 90 meters in 15 seconds. What is the runner's average speed?
6 m/s.
A backpack is lifted from the floor onto a shelf. Which type of energy increases?
Gravitational potential energy.
Which particle has a positive charge?
A proton.
A musician plays a note with a higher frequency. What happens to the pitch?
The pitch becomes higher.
A geologist finds a rock feature cutting across multiple existing layers. What is this feature called?
An intrusion.
A vehicle changes from 0 km/h to 500 km/h in 10 seconds. What is its acceleration?
50 km/h/s.
At the very bottom of a pendulum or swing, which type of energy is at its maximum?
Kinetic energy.
Which particle has an electric field that points inward toward itself in a electric field?
An electron.
What unit is the frequency of a wave measured in?
Hertz (Hz).
A rock layer containing fish fossils is found above a layer containing trilobite fossils. Which fossils are older, and how do you know?
The trilobite fossils are older because they are in the lower layer relative to the rock layer containing the fish fossils.
A 50 kg object is pushed with a force of 200 N. What is its acceleration?
4 m/s².
As a skydiver falls toward Earth before opening a parachute, what happens to gravitational potential energy?
It decreases.
A magnet is able to pick up a paper clip through a sheet of plastic. What does this tell us about magnetic fields?
They can pass through some non-magnetic materials.
A sound becomes louder, but the pitch stays the same. What changed in the wave?
The amplitude.
A dinosaur fossil is found in a rock layer exposed at Earth's surface today. What most likely happened to some of the layers that were above it?
They were eroded away.
Two objects are pushed with the same force. One object has three times the mass of the other. Which object will accelerate more? Explain.
The object with less mass because larger masses need more force to achieve the same acceleration.
Explain what happens to both gravitational potential energy and kinetic energy as a roller coaster moves from the top of a hill to the bottom.
Gravitational potential energy decreases while kinetic energy increases.
Three lights are connected in a parallel circuit. One light is switched off. What happens to the other two lights, and why?
They stay on because each branch has its own independent path.
Astronauts can see each other through space but cannot hear each other speaking. Why?
Sound requires a medium to travel, but light does not.