# Question about acceleration/forces

#### Banana15

My homework question asks...
"If you stand next to a wall on a frictionless skateboard and push the wall with a force of 30 N, how hward does the wall push on you? If your mass is 60 kg, what is your acceleration?"
I figured that the wall pushes on you with a force of 30 N back, but what is the net force to be used in the equation to find acceleration? Is it 0, or 30?

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#### wisredz

Try to imagine the problem. What would happen if YOU were in the same position. Would you stand still? No. So use 30=60.a

#### geosonel

Banana15 said:
My homework question asks...
"If you stand next to a wall on a frictionless skateboard and push the wall with a force of 30 N, how hward does the wall push on you? If your mass is 60 kg, what is your acceleration?"
I figured that the wall pushes on you with a force of 30 N back, but what is the net force to be used in the equation to find acceleration? Is it 0, or 30?
only 1 horizontal force is acting on you -- that of the wall pushing back on you with 30 N force.

the "other" horizontal force (you pushing the wall) is not acting on you, but rather is acting on the wall

to calculate horizontal acceleration, use F = ma

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#### Banana15

You wouldn't stand still, so it would be 30 divided by 60?

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#### Banana15

geosonel said:
only 1 horizontal force is acting on you -- that of the wall pushing back on you with 30 N force
the "other" horizontal force (you pushing the wall) is not acting on you, but rather is acting on the wall

now use F = ma
thanks that really clears things up!

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