Physics help....again

[princedylan101]

Ok so I am doing some homework, and there is one problem that I just can not solve. Can someone please help me out??

[JeffreyEagan]

I'm gonna give you a tool our ancestors used. http://www.wolframalpha.com/

[princedylan101]

I'm gonna give you a tool our ancestors used. http://www.wolframalpha.com/

How would I plug my question into it?

 

700Mhz?

Uhh....it's supposed to be in m/s.

[aduman]

Ok so I am doing some homework, and there is one problem that I just can not solve. Can someone please help me out??

 

What is the gravitational constant of the Moon? Exact value is needed to solve this. Sorry I'm from EU.

[princedylan101]

What is the gravitational acceleration of the Moon? This is needed to solve this. Sorry I'm from EU.

I think it's 1.6m/s^2

[bobhays]

Use the kinematics equations (just google it). Look for the one that fits what you need. Distance traveled is 310km, acceleration is the -gravity on the moon. Final velocity is 0 (stops at 310km), you need to find initial velocity.

[aduman]

I think it's 1.6m/s^2

 

Like I said I'm from EU so bear with me:

 

You should use, v^2=vi^2 - 2ax

 

x=310000m

 

a=1,6m/s^2 (I'm not sure about this.)

 

v=0 (since the projectile stops at the end), 0 = vi^2 - 2x1,6x310000       (not 310km as we should use 'meters(m)' as the unit to come up with something in m/s)

 

vi = 995,991 m/s

 

Hope this helps!

[princedylan101]

Like I said I'm from EU so bear with me:

 

You should use, v^2=vi^2 - 2ax

 

v=0, 0 = vi^2 - 2.1,6.310000

 

vi = 995,991 m/s

 

Hope this helps!

Answer turned out to be 923m/s. I have no clue how.

[Arphenyte]

Wouldn't it be 0? Since the problem says the projectile was "launched" meaning from rest? D:

[aduman]

Answer turned out to be 923m/s. I have no clue how.

 

The constant is probably something different than 1,6m/s^2.

 

Which turns out to be around 1,37 if we take 923 as the answer.

[JeffreyEagan]

Wouldn't it be 0? Since the problem says the projectile was "launched" meaning from rest? D:

Theoretically, the launch speed should be 0m/s as it would be at rest. Thus not having velocity.