1st grade science experiment question...

Thread Starter

shadow4dog

Joined Jan 27, 2015
6
I have a family member with a 1st grader who was interested in creating a science experiment with an electricity kit. Basically, it's from the sciencewiz kit. Attaching a D battery to a small light bulb and measuring levels left on the D battery. Tested against the small motor with pinwheel and following the same process. Of course, the pinwheel motor registers 'less' on the multimeter. Is it correct (for a 1st grader) to say that the motor uses more 'energy' from the battery than the light??? There is a lot of vocabulary that he doesn't have for experiements with electricity, but this is what he was interested in.....Thank you!
 

joeyd999

Joined Jun 6, 2011
4,394
Yea! A kid after my own heart. Buy him lots of this kind of stuff and he'll quickly figure it out on his own.

If I read you correctly, the "levels" the meter is measuring is called current. Roughly speaking, higher current means higher power (more energy vs. time). So, if the motor show less current than the light bulb, then it is using less power.

Technically, Power = Current (measured on the meter) times the Voltage (of the battery, roughly 1.5V). And Energy = Power times Time. He doesn't need to know this yet, but you can put it in your pocket for later.
 

wayneh

Joined Sep 9, 2010
16,390
Just a thought - forget about quantitation and focus on a phenomenon. A voltage reading on a meter is not terribly exciting and maybe too abstract for a little kid. Maybe demonstrate how LEDs make more light with the same power as an incandescent? If this is a competition, this is sure to attract the green teacher's nod of approval.
 

joeyd999

Joined Jun 6, 2011
4,394
A voltage reading on a meter is not terribly exciting...
Say it isn't so! My grandfather gave me his old 20Kohm/volt analog when I was 5 -- it was the greatest thing since milk and cookies!

You cannot imagine how many ways I tried to make that needle move.
 

wayneh

Joined Sep 9, 2010
16,390
Ahh, well, a moving needle is completely different. Much more fun. My mom gave me an old light meter, from back in the day when you needed one to take photos, and I had a blast using it with small solar cells.

I'm not anti-meter. I just think something real the kids can see will have more impact than comparing numbers.
 

MrChips

Joined Oct 2, 2009
21,112
That's great that you can get a kid interested in science. But let's not go overboard here.
I guess a 1st grader is about 5 years old.

What electricity experiment can a 5-year old do that he/she can understand?

The only thing that comes to mind is the difference between series and parallel circuits.

See if you can acquire two or four of the same 1.5V light bulb.

Assemble one circuit with two bulbs in series with the D-cell.

Assemble a second circuit with two bulbs in parallel with the D-cell.

Get the kid to understand and explain to an observer how the brightness of the blubs in the two circuits differ.
 

MrChips

Joined Oct 2, 2009
21,112
Build a simple current/volt detector using a coil of magnet wire wrapped around a toilet roll. Place a small compass at the center of the coil and connect the coil to the D-cell.
 

joeyd999

Joined Jun 6, 2011
4,394
That's great that you can get a kid interested in science. But let's not go overboard here.
I guess a 1st grader is about 5 years old.

What electricity experiment can a 5-year old do that he/she can understand?
MrChips,

My career started at 5 years old with a Science Fair Crystal Set Radio Kit from Radio Shack that my grandma gave me for Christmas. Within a year, I was well beyond anything that any of my family understood. I am not saying that this kid is/will be the same. I am just suggesting that if he really has an interest in it he will guide himself. Kids do that.

My suggestion is just keep getting him stuff as long as he is interested in it. And let him take it as far as it goes. It's not spoiling him...just encouraging his own exploration of his interests where ever it takes him.
 

GopherT

Joined Nov 23, 2012
8,012
I have a family member with a 1st grader who was interested in creating a science experiment with an electricity kit. Basically, it's from the sciencewiz kit. Attaching a D battery to a small light bulb and measuring levels left on the D battery. Tested against the small motor with pinwheel and following the same process. Of course, the pinwheel motor registers 'less' on the multimeter. Is it correct (for a 1st grader) to say that the motor uses more 'energy' from the battery than the light??? There is a lot of vocabulary that he doesn't have for experiements with electricity, but this is what he was interested in.....Thank you!
Simply, yes. You can say the motor uses more energy that that specific bulb.

We can get into the math and the detailed physics if you want but you are on the right path with him in my opinion - just say YES. The motor is using more energy and the battery's voltage sags more than when the light is connected.
 

Thread Starter

shadow4dog

Joined Jan 27, 2015
6
Thank you all for your great responses!!! We're at the park right now...when I get home I'll upload a pic that may explain myself better.. :) but here's how it went. Tested the battery first..with a reading of 1.55. Then connected the light bulb and tested the battery..got a reading of 1.48..then repeated with the little motor and pin wheel..with reading of 1.42. He gets numbers pretty well and can ignore the decimal. So, does the motor causes more resistance? Or utilize more energy?? And to the idea of having a devise to use, he's testing all things..including people:)
 

GopherT

Joined Nov 23, 2012
8,012
Thank you all for your great responses!!! We're at the park right now...when I get home I'll upload a pic that may explain myself better.. :) but here's how it went. Tested the battery first..with a reading of 1.55. Then connected the light bulb and tested the battery..got a reading of 1.48..then repeated with the little motor and pin wheel..with reading of 1.42. He gets numbers pretty well and can ignore the decimal. So, does the motor causes more resistance? Or utilize more energy?? And to the idea of having a devise to use, he's testing all things..including people:)
The motor is less resistance and lets more amps flow (like a bigger water pipe would allow more water to flow).
 

MrChips

Joined Oct 2, 2009
21,112
Thank you all for your great responses!!! We're at the park right now...when I get home I'll upload a pic that may explain myself better.. :) but here's how it went. Tested the battery first..with a reading of 1.55. Then connected the light bulb and tested the battery..got a reading of 1.48..then repeated with the little motor and pin wheel..with reading of 1.42. He gets numbers pretty well and can ignore the decimal. So, does the motor causes more resistance? Or utilize more energy?? And to the idea of having a devise to use, he's testing all things..including people:)
Even some university science grads cannot correctly explain this phenomenon. I wouldn't want to have to explain it to a 5-year old.

How about using a bulb and D-sized cell and see how long it lasts. Then try a C-sized , AA and AAA and compare duration before the bulb goes out?
 

Thread Starter

shadow4dog

Joined Jan 27, 2015
6
When this was started..it seemed like a cute little idea..but the verbage is difficult. It may be that it becomes.'how long will the light bulb' last:) it seems to be that what is being measured or pulled out from the battery, also has a time component to it:) yikes!
 

Thread Starter

shadow4dog

Joined Jan 27, 2015
6
Yes..we may have to back up a bit:) I think what he really did, given the readings he got, was find out that the motor would drain the battery quicker than the little light....but that would have been a different set up:)
 

Thread Starter

shadow4dog

Joined Jan 27, 2015
6
Simply, yes. You can say the motor uses more energy that that specific bulb.

We can get into the math and the detailed physics if you want but you are on the right path with him in my opinion - just say YES. The motor is using more energy and the battery's voltage sags more than when the light is connected.
Thank you~~ I had to go back over responses again! I think the idea of 'sag' or 'pull' is what I was trying to say. Also, after they were playing on a merry-go-round at the park (a loop) and were all taking turns stopping it (resistance/load) that this might be a better concrete example for him:)
 
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