A shopper in a supermarket pushes a loaded 32kg cart with a horizontal force of 12N.

Questions:
a. how far will the cart move in 3.5s, starting from rest? (disregard friction.)
b. how far will the cart move in 3.5 s if the shopper places an 85N child in the cart before pushing?

Answers:
a. 2.3m
b. 1.8m


Thought I could do this problem but when I try I never seem to get the right answer. How do I find the right answer?

Quote:

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Originally Posted by malic

a shopper in a supermarket pushes a loaded 32kg cart with a horizontal force of 12N.

questions:
a. how far will the cart move in 3.5s, starting from rest? (disregard friction.)
b. how far will the cart move in 3.5 s if the shopper places an 85N child in the cart before pushing?

answers:
a. 2.3m
b. 1.8m


thought i could do this problem but when i try i never seem to get the right answer. how do i find the right answer?

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a. Determine the acceleration.
F = m*a

To find distance use
x = Vo*t + (1/2)*a*t^2
where Vo = 0

b. Determine the acceleration (the mass is higher now). Everything else is done the same as above. But... I can't get the answer you say it should have. I got a. right. So I think your answer for b is wrong. See if you can get 0.63 m

Quote:

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Originally Posted by tjsail

a. Determine the acceleration.
F = m*a

To find distance use
x = Vo*t + (1/2)*a*t^2
where Vo = 0

b. Determine the acceleration (the mass is higher now). Everything else is done the same as above. But ... I can't get the answer you say it should have. I got a. right. So I think your answer for b is wrong. See if you can get 0.63 m

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I think b is right. I did what you told me to and I got 1.8. thank you again I'm so far behinde in this class its not even funny.

32kg+8.5kg= 40.5kg

12/40.5= 0.2962962963

.5*0.2962962963*3.5^2 = 1.814814815

so about 1.8m