Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!


Answers:
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1. D. All bodies are attracted to other bodies by gravity. But a body has to be really stinkin’ big before it’s noticeable.


2. FALSE!!! Gravity accelerates all things at the same rate. All things fall at the same rate of speed no matter what (ignoring air resistance, that is).


3. True. That’s why some things weigh more then other things. Gravity pulls more on the big stinky guy sitting next to me on the bus, then it does on me.


4. They hit the ground at the same time. Gravity accelerates all things equally.


5. The monkey and the dart fall downward at the same rate of speed. So the dart would hit exactly where the biologist aimed! In fact, if the monkey didn’t let go, the dart would have hit lower then the biologist aimed.


6. They do…if you’re on the moon! On Earth, the friction between the air and the feather causes the feather to slow down and the brick to win the race.


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For advanced students:

I’ve converted feet/second to miles/hour for you so that you can get more of a feel for the speed.


1. 96 ft/s which is 64 mph


2. 192 ft/s or 131 mph (thatsa fasta meata balla!)


3. 128 ft/s or 87 mph (remember that you have to half the time. It took 4 seconds to go up and 4 seconds to fall down.


4. 400 ft. Ok, so, you have a big house!


5. 144 ft Nice catch!
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Comments

6 Responses to “Unit 1: Mechanics (Gravity) Answers to Exercises”

  1. Good question! What do YOU think?

  2. Zohra Mohajir says:

    Question no.5 -If the monkey didn’t let go, Why would the dart hit lower than the biologist aimed?

  3. What specifically did you have trouble with?

  4. Gladys Acevedo says:

    Hi

    I don’t get the answer of the question number 5. Could you explain it?

  5. I should have clarified, because you’re right – the golf cart would experience more air drag than the golf ball. Okay, so ignore air drag. Now who wins?

  6. christine turpin says:

    On question number 4 under gravity excercises wouldnt the golf cart fall last as it has a different size compared to the golf ball