If all the objects have around the same mass, which of the following objects has the most gravitational potential energy? Question 4 options:

a chair set on the ground

a book on a high shelf on the first floor of a house

a ball stuck on the roof of a two-story house

a cat investigating a basement

Question 5 (1 point)
Which of the following electromagnets would have the greatest magnetic field?

Question 5 options:

A

B

C

D

Question 6 (1 point)
What is the role of a turbine in an electric generator?

Question 6 options:

It stores energy for later use.

It releases chemical energy.

It transfers electrical energy.

It provides mechanical energy.

Question 7 (1 point)
Which energy transformation takes place in a generator?

Question 7 options:

mechanical to electrical

chemical to radiant

electrical to mechanical

radiant to electrical

Question 8 (1 point)
The rumble feature on a video game controller is driven by a device that turns electrical energy into mechanical energy. This device is best referred to as ?

Question 8 options:

an electric generator

an electromagnet

a solenoid

a motor

I do not know it sorry

Explanation:

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

b.

the accuracy of the data.