Homework Statement
An xyz coordinate system contains three charged particles: particle 1, q1=− 6.5μC , at (4.0 m,-2.0 m, 0); particle 2, q2 = 12μC , at (1.0 m,2.0 m, 0); and an electron at at (-1.0 m, 0, 0).
Determine the x, y, z components of the vector sum of the vectors of the electric...
Homework Statement
The line L
L1: x=3+2t, y=2t, z=t
Intersects the plane x+3y-z=-4 at a point P. Find a set of parametric equations for the line in the same plane that goes through P and is perpendicular to L.
Homework Equations
cross-product
r=r0+t(vector) this is to get in parametric form...
Okay now I am lost... :( I'm assuming I did part a incorrectly then because when P'(t)=e-.05449048t letting t =20 I get a population of 127.97... doesn't make sense.
When I use my k value for P(20)=(1000)/(1+7e-.054545034(20)) I get a population of 298.38 which seems much more reasonable.
EDIT*...
Okay so I got my k value to be (-1/5)ln(421/553) which is approximately 0.0545. The 298.38 came from the fact of using that value in P(20), which just gives me the population of giraffes in 1990... which is not what the question is asking I now realize *facepalm*
but plugging that k value into...
Yes my mistake, the equation should be as you stated. I guess I'm confused about what function to use to differentiate, am I supposed to solve the differential equation
dP/dt=kP(1-(P/M)?, I'm assuming I would use the k value I found in my first post. In that case I suppose I would just...
Okay so deriving that function I got:
P'(t)= (7000e-kt)/(1+7e-kt)^2
I found my value of k to be (1/5)ln(421/553)
Plugging in that value and letting t=20 years the answer was 4.3*10-4
I'm assuming part a) and part b) should be equivalent. Can you give me any advice on what I'm doing wrong? I...
Sorry I forgot the parenthesis on that one yes, it is M/(1+Ae-kt)
I guess I'm not sure exactly what the question is asking, do I just use the above formula and derive it to get the rate of change? Would I have to find a value of k first or just leave it as a constant?
Homework Statement
The growth of a giraffe population on an island follows a logistical growth model. The maxium giraffe population on the island is estimated at 1000. The population was first measured in 1970 at 125. Then in 1975 the population was 158
a) Find the rate of change in the...
Well I'm at a loss of how to even begin my calculations, I'm having trouble with how to approach the problem, my book isn't doing very well on this topic for me and my professor is essentially a proctor for tests, I tried khan academy with little luck. Should I be setting up three reference...
Homework Statement
All three disks are made of sheet metal of the same material, and the diameters are 1.2m ,2.4m , and3.6m . Assume that the x-axis has its origin at the left-most point of the left-most object and it points to the right.
A)
Determine the location of the center of mass of the...
Homework Statement
A 1200-kg car is backing out of a parking space at5.5m/s . The unobservant driver of a 1900-kgpickup truck is coasting through the parking lot at a speed of 4.0m/s and runs straight into the rear bumper of the car.
What is the change in internal energy of the two-vehicle...
Thank you for your reply, but I'm wondering when calculating the coefficient of restitution which is e=(V12xf)/(v12xi) isn't zero or am I missing something? Isn't the velocity of the two cars 9.33m/s? Shouldn't it actually be zero for e to =0?
Homework Statement
A 2000-kg truck is sitting at rest (in neutral) when it is rear-ended by a 1000-kg car going 28m/s .After the collision, the two vehicles stick together.
#1What is the final speed of the car-truck combination?
#2What is the kinetic energy of the two-vehicle system before the...