Review Force and Lab Safety

1. Students were given samples of simulated Martian soil to observe, describe, and investigate for any evidence that may indicate that life existed at one time. Based on the problem being investigated and the data collected, what type of investigation did the students conduct?

• Descriptive
• Comparative
• Experimental
• Conclusive

2. All of the following statements concerning when and how to use an eyewash are true EXCEPT:

• Flush the eyes with water for a minimum of 15 minutes.
• Keep the eyes closed while flushing with water.
• Know the location and how to use the eyewash before handling chemicals.
• After flushing with water, the school nurse should examine the eyes to determine if further treatment is needed.

3. A fire blanket is used for:

• Smothering flames when someone’s clothing or hair catches fire
• Absorbing chemical spills
• Extinguishing large fires
• Protecting clothing and skin from chemical burns

4. A student mixed baking soda with lime juice. Which of the following observations is evidence that a chemical change has taken place?

• The mixture has the color of the lemon juice.
• The mixture tastes sour.
• A gas is released and is seen as bubbles.
• The baking soda can no longer be seen.

5. Which of the following questions CANNOT be used to decide whether a chemical change has taken place?

• Was there any precipitate formed?
• Was there a change in size?
• Was there a production of gas?
• Was there a change in thermal energy?

6. Which of the following is NOT an example of a chemical change?

• A glass falling down and shattering on the ground
• Sodium metal bursting into flames when placed in water
• Burning of coal
• Tarnishing of silver

7. Which image shows how Earth’s gravity acts on the falling ball?

• A
• B
• C
• D

8. What is the net force on the object shown in the picture below?

• 180 newtons toward left
• 100 newtons toward right
• 40 newtons toward left
• 0 newtons

9. Team A and B are in a tug of war competition. The force applied by each team is represented by an arrow. What will be the direction of the net force acting on the rope?

• The net force will act towards Team B.
• The net force will act towards Team A.
• The net force will act in a downward direction.
• No net force will act on the rope.

10. Alex is pushing a heavy box. The force he exerts is represented by the arrow. In order to make his task easier, in which direction should an additional force be applied?

• A
• B
• C
• D