Name:______________________________________ Period:________ Final Exam Date:_______
8th Grade Science First Quarter Final Study Guide – Answer Key
Complete all questions on a separate sheet of paper
Unit 1: Experimental Design
1. What is the volume that is indicated on the picture of the graduated cylinder? 73 mL
Use the line graph below to answer questions 2 -6:
2.
3.
4.
5.
6.
What is the independent variable shown in the graph? The months of the year
What is the unit of measurement for the independent variable? Time in months
What is the dependent variable shown in the graph? Weight
What is the unit of measurement for the dependent variable? Kilograms
What is the total amount of weight Sam gained from February to April? 15 kilograms
7. A student noticed that a wind chime stopped making noise when the fan was turned off.
The student then suggested that the wind generated by the fan made the wind chimes
move to make sound. This suggestion is also known as what part of experimental design?
The suggestion made was a hypothesis because it is based on observations
Read the following experiment to answer the questions 8 - 11:
An experiment was designed to determine if special juice was would increase the
productivity of workers in a box-making factory. Two groups of 50 workers each are
to make as many boxes as they can in an hour. Group A was given the special juice
and Group B was not given the special juice. After an hour, the investigator counts
how many boxes were made. Group A made 1, 789 boxes and Group B made 1, 523
boxes.
8. What is the independent variable in this experiment? Special Juice
9. What is the dependent variable in this experiment? The amount of boxes made
10. What is the control in this experiment? Group B, because they did drink the juice
11. What are three constants in this experiment? Same boxes, same amount of time, same
amount of workers.
12. List the steps of experimental design in logical order. Define the problem, form a
hypothesis, perform the experiment and gather data, form a conclusion.
13. What is a controlled experiment? Why do we need to have controlled experiments? A
controlled experiment tests the effect of ONE INDEPENDENT VARIABLE
Name:______________________________________ Period:________ Final Exam Date:_______
14. How many independent variables should a controlled experiment have? Explain why. Only
ONE independent variable should be used because, if you had more than one variable, the
scientist wouldn’t know which variable caused the change.
Unit 2: Kinetic Energy and Mass
15. How much would the kinetic energy increase if you doubled the speed (or velocity)? The
kinetic energy will quadruple.
16. Draw a basic graph that would show the relationship between kinetic energy and velocity.
17. If temperature is the measure of the kinetic energy of an object, then what would happen if
the temperature increased? What would happen if the kinetic energy decreased?
The kinetic energy will increase if the temperature increases. The kinetic energy will decrease
if the temperature decreases.
18. A bowling ball and a marble move down a ramp in the same direction and at the same
speed. Both the bowling ball and the marble slow down because of the equal force of
friction. How would you describe why the bowling ball would need more distance to stop
than the marble? The bowling ball needs more distance to stop, compared to the marble,
because it has more mass.
19. Define acceleration and give an example of it. Acceleration is the change in speed and /or
change in direction. The motion of two bicycles accelerating in a straight line differs from
the motion of a bicycle moving in a straight line at a constant speed because the change in
velocity is divided by the time for that change.
20. Make a prediction based on the diagram below:
21. What do you think would happen if Marta who has a mass of 50 kg pulled on Ryan who
also has a mass of 50 kg? Both skateboards will move towards each other.
22. The graph below shows the distance traveled by a motorcycle over 30 seconds. What
happened to the motion of the motorcycle between t = 3 s and t = 11 s? The object
traveled 8 m at a constant speed
23. What happened to the motion of the motorcycle between t =11 s and t = 16 s? The object
stopped moving for 5 seconds.
Name:______________________________________ Period:________ Final Exam Date:_______
24. What two units would you need to determine an object’s speed? The two units needed to
determine speed are distance and time.
25. The diagram below shows a roller coaster with several positions labeled. Which starting
position will cause the roller coaster to have the greatest speed? Why? F, because it will
have the most potential energy to convert to kinetic energy.
26. What could cause the roller coaster to go faster? Increasing Mass
27. What is the difference between speed and velocity? Speed is the distance measured over
time and Velocity is speed in a given direction.
28. What is the formula for speed (velocity)? Distance? Time? Speed = distance ÷ time,
Distance = Speed × time, and Time = Distance ÷ speed
29. How much time do you need for a skateboard to travel a distance of 200 m at 10 m/s?
Time = distance ÷ time, 200m ÷ 10 m/s = 20 seconds
30. What is the speed of the object in the following graph?
Speed = distance ÷ time, 30m ÷ 15s = 2 m/s
d
s
t
Name:______________________________________ Period:________ Final Exam Date:_______
31. Three identical shopping carts are positioned at the top of a ramp. Which shopping cart
will travel the farthest? Why? The 30kg cart because it has the most mass. The more
mass the further the cart will travel.
30 kg
20 kg
10 kg
Distance (m)
32. You measured the mass of three water bottles. Each bottle is the same size but with a
different mass, as shown in the chart below.
Water Bottle
Mass (g)
1
100 g
2
200 g
3
300 g
One at a time you release the water bottles from the starting point on the ramp. You
record the amount of time it takes for each bottle to reach the end of the ramp. Which
water bottle do you think would take the longest amount of time to get to the bottom of the
ramp? Why? Water bottle number 3 because it has the most mass.
33. What is the kinetic energy of a bowling ball that is 20 kg, rolling down the aisle at a velocity
of 10 m/s? KE = 1/2m × v2 , KE = (½ 20kg) × (10 m/s)2 . The kinetic energy of the bowling
ball is 1,000 Joules
34. What is the velocity of a remote control helicopter that has a kinetic energy of 10,500
Joules and a mass of 10kg? KE = 1/2m × v2 , 10,500 J = (½ 10kg) × (m/s)2 . The mass is
46 kg.
35. How would you set up a graph to display the speed of a racecar? What would go on the xaxis? What would go on the y-axis? What type of graph would you use?
Time (seconds)