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I've been given a challenge by my grade 11 physics teacher and I can't make heads of tail of it, I’ve got the formulas but the numbers don't make sense.

If you went up 109 km (above sea level) and dropped a rock, what speed would it be traveling at and how long would it take to reach 34 km (above sea level). Air resistance can be ignored.

Gravitational constant

=9.79 m/second*second

This is the only formulas he gave me.

Where do I even start???

Distance:

Distance to be traveled = 109km - 34km

Distance to be traveled = 75km

I then started making a chart going by 0.5 second increments

Example:

{Time} (Acceleration) [calulation]

{0.5 sec} (39.16m) [9.79/(0.5*0.5)]

{1 sec} (9.79) [9.79/(1*1)]

{1.5 sec} (4.35) [9.79/(1.5*1.5)]

{2 sec} (2.44) [9.79/(2*2)]

{2.5 sec} (1.57) [9.79/(2.5*2.5)]

{3 sec} (1.09) [9.79/(3*3)]

So could someone tell me is this is right

After 3 seconds, the rocks velocity is 58.4 M/S and traveled a distance of 156 meters

I got the distance by taking the time

{Time} (Acceleration) <Current speed> [calculation]

{0.5 sec} (39.16m) <39.16 m/s> [39.16]

{1 sec} (9.79) <48.95 m/s> [39.16+9.79]

{1.5 sec} (4.35) <53.30 m/s> [48.95+4.35]

{2 sec} (2.44) <55.75 m/s> [53.30+2.44]

{2.5 sec} (1.57) <57.32 m/s> [55.75+1.5]

{3 sec} (1.09) <58.40 m/s> [57.32+1.09]

I got my distance traveled by summing up my current speeds and deviding the total by 2 (2 samples per second speed is in meters per second)

My total speed is the total of my currentspeed

First thing is that correct?

Second thing is this is correct is there a better way of doing this?

If this is not correct, what is the correct calculation?

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# Homework Help: Gravitational acceleration

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