I am hoping I have this right but want to make sure.
I have 9x10^9 x N x m^2/C^2 and want to use units of cm and μC (micro)
9x10^9 x N x 1m^2/1C^2 x 10000cm^2/1m^2 x 1C^2/1x10^12μC^2
9x10^9 x N x 10000cm^2/1x10^12μC^2
90 x N x 1cm^2/1μC^2
Have I got that right? Havent fallen into any...
Homework Statement
where does the gravity cancel out between the Earth and moon?Homework Equations
s=3.84405x10^8m
earth m = 5.98x10^24kg
moon m =7.35x10^22kg
G = 6.67x10^-11N m^2/kg^2
mass of object between = 1kg for simplicity
F = G x m / r^2
r = ?
F Earth = F moon
G x Earth / r^2 = G x moon...
person 1, 100kg 10m/s. person 2 50kg (made these up on spot)
KE = 50kg x 100m/s
KE = 5000kJ
(person 2 has 0)
post collision, 150kg, 6.7m/s
KE = 75kg x 44.89m/s
KE = 3366.75kJ
a person double the mass and half the velocity only has a KE of 2500kJ?
heat, sound and things.
but a higher kinetic energy results in more "damage", where as the person will still be knocked back at the same velocity as momentum is the same. I can't quite get my head around it :/
Homework Statement
What is more likely to cause greater injury, a collision with a light person at fast speed or a person with twice the mass at half the velocity?
Homework Equations
momentum = mv
KE = 1/2mv^2
The Attempt at a Solution
I am having a little trouble at which is...
Do you mean m1+m2? I did the exercise again using my own way of things and ended up with the right answer.
force 1 (gravity and m2) - force 2 (m1 down the incline) / m1+m2 (as in f=ma or a=f/m)
=2.9m/s/s
which is the answer the book gives, I think i have the idea of tension figured out now...
One thing I enjoy as a new physics student is using formulas. I have been playing with the fundamental formulas in terms of units rather than their names.
That is instead of a=v/t
m/s/s=(m/s)/s
or v=at
m/s=(m/s/s) x s
m/s=m/s
Simple maths yea, but when I am getting to the bigger...
ill look at above post over the next while and see what I can get from it thanks :).
just figured out problem 2 on my own, i was rearranging it wrong.
s= ut + (0.5) x a x t^2
s/a = ut + (0.5) x t^2
2s/a = ut + t^2
no initial velocity so ut = 0
t^2 = 2s/a
I can manage that for easier problems, but if you look at what I am having trouble with is what equation to use at the right time and how to get there/know that its that one to use.
just to add, friction, pressure and electrostatic forces I have not encountered yet :( simply having trouble with...
Ok this will be a long post, sorry in advance. I am an online student of a university and the help I am getting from them is ridiculous, I am also using a book called quicksmart introductory physics, and for the most part it is quite rubbish.
1st Problem: (not homework questions, I am trying...