# Calculating the upward force

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1. Nov 2, 2016

### BrodieEX

1. The problem statement, all variables and given/known data

Gr.11 Physics, about 2 months in so I don't know much.

Bob pitches his calculator in to the air and watches it rise to a height of 5 meters above the floor, and rebound to a height of 4 meters. The calculator was in contact with the floor for ten milliseconds, and it has a mass of 500 grams. Calculate the upward force exerted on the calculator by the floor.

2. Relevant equations

Here's all the equations I think would be relevant?:

Fn = Fg
Fg = mg
Ff = uFn
Fnet = ma

3. The attempt at a solution

I'm not entirely sure where to start with such little info. I tried to get the Force of Gravity (Fg) like this:

Fg = mg
= (0.5kg)(9.8)
= 4.9N

But I feel like the fact that it was accelerating towards the ground would increase that?

Any help is appreciated.

2. Nov 2, 2016

### haruspex

No, none of those are interesting here.
Does SUVAT mean anything to you?
What about a relationship between force and momentum?

3. Nov 2, 2016

### BrodieEX

No, and no :/ My teacher has a habit of giving us questions for things he hasn't taught us yet. Could you explain?

4. Nov 2, 2016

### BrodieEX

Ah I found a video on exactly what I was looking for. I got it now :)

5. Nov 2, 2016

### Kaura

Try to calculate the velocity right before and after the calculator hits the floor and see if you can use this to figure out the force