Which of these common phenomenon represents the Doppler effect?
A.
the way canyons and auditoriums create echoes
B.
the way sound is distorted if you listen to it underwater
C.
the changing pitch in the sound of airplanes flying overhead
D.
perfect pitch
C. the changing pitch in the sound of airplanes flying overhead represents the Doppler effect.
Which of the following is an example of chemistry in forensic science?
A.
estimating the trajectory and impact of bullet
B.
extending DNA strands to match samples
C.
calculating the force needed for a body to have fallen at a specific location
D.
using blood spatter patterns to establish how a body was stabbed
B. Extending DNA strands to match samples is an example of chemistry in forensic science.
Fundamentally, what is a catalyst in a reaction?
A.
a reactant
B.
a product
C.
It is both a reactant and a product
D.
It is neither a reactant nor a product
D. A catalyst is neither a reactant nor a product in a reaction.
Ash is investigating the scene of a car crash between a semi-truck and a small Volkswagen. Based on traffic cameras, both vehicles were going the same speed at the time of the collision. Which vehicle had more momentum?
A.
It’s impossible to tell.
B.
The car did because it has less mass.
C.
They had the same momentum.
D.
The semi did because it has more mass.
D. The semi-truck had more momentum because it has more mass.
Last summer, it took a group of friends about two hours to hike up a small peak in the Rocky Mountains. This year, they are doing the same hike, but this time, they will be carrying 40-pound backpacks. Why should they expect it to take longer this time?
A.
It’s cooler this summer.
B.
Newton’s Second Law of Motion
C.
You’re not as in shape as you were last summer.
D.
Newton’s Third Law of Motion
B. Newton's Second Law of Motion explains why the group of friends should expect it to take longer to hike up with the 40-pound backpacks. The backpacks will add mass, and therefore, the group will have to exert more force to move up the peak, making the hike more difficult.
A boulder that’s poised at the top of a hill, ready to roll down at any second, contains what type of energy?
A.
stored mechanical energy
B.
motion energy
C.
gravitational energy
D.
kinetic energy