Force and Motion
What is a push or pull that can change an object's motion?
Force
What structure is considered the basic unit of life?
What star is at the center of our solar system?
The Sun.
What are the three common states of matter?
solid, liquid, and gas
What is a testable explanation for an observation or question?
hypothesis
What is the speed of an object if it travels 20 meters in 4 seconds?
5 meters per second
What process do plants use to make their own food using light energy?
Photosynthesis
What causes day and night on Earth?
Earth's rotation
When ice melts into liquid water, has a new substance been created?
no; it is a physical change
Which tool would be best for measuring the volume of a liquid?
graduated cylinder
Two students push a box in opposite directions. One pushes with 50 N and the other with 30 N. What is the net force?
20 N in the direction of the 50 N force
In a food chain, what organism makes its own food and provides energy to other organisms?
Producer
What causes the different seasons on Earth?
Earth's tilted axis as it revolves around the Sun
What happens to the particles in a substance when thermal energy is added?
the particles move faster
In an experiment, the variable that a scientist intentionally changes is called what?
independent variable
A soccer ball is sitting still. A player kicks it, and it begins moving. What caused the ball's motion to change?
Unbalanced Force
A population of rabbits suddenly has access to much more food. What will most likely happen to the rabbit population?
The population will increase
You observe the Moon getting brighter each night until it appears completely lit. What phase comes next?
Waning
A substance changes from a liquid to a gas. What phase change occurred?
vaporization/evaporation
A student tests whether different amounts of fertilizer affect plant growth. What should the student measure to determine the effect of the fertilizer?
plant growth/height
Two identical toy cars are pushed with different amounts of force. Car A receives 10 N and Car B receives 30 N. Assuming friction is the same, which car will accelerate more?
Car B
A disease kills most of the plants in an ecosystem. Predict one effect this could have on organisms that depend on those plants for food.
Their populations could decrease because less food is available.
Why do we see different constellations during different times of the year?
Earth’s revolution around the Sun, which changes the part of space we see at night
A student says, "When water evaporates, the water molecules disappear." Is this correct? Explain.
no; the molecules remain but spread out as a gas
A scientist repeats an experiment three times and gets similar results each time. Why is this useful?
What is it increases confidence that the results are reliable and not due to chance?