Homework Statement
A world-class runner can complete a 100 m dash in about 10s. Past studies have shown that runners in such a race accelerate uniformly for a time tu and then run at constant speed for the remainder of the race. A world-class runner is visiting your physics class. You are to...
Thanks for you help Doc. I fixed the value for the spring constant and got 800N/s. I also reviewed my notes on springs, and found that period is equal to 2(pi)√m/k That would mean T = 2(pi)√8kg/800N/m = .6283s -> f = 1.59 Hz. Does that sound right?
Homework Statement
An ideal spring of unstretched length .20m is placed horizontally on a frictionless table as shown above. One end of the spring is fixed and the other end is attached to a block of mass M = 8.0kg. The 8.0kg block is also attached to a massless string that passes over a small...
Homework Statement
Someone places a 6.0m long steel rod on a rock so that one end is under a baby moose weighing 2.0 kN. THe person pushes down on the other end of the rod with a force of 400N, and the moose is held in the air at rest. The rock was:
(a) 1.0m from the moose
(b) 5.0m from the...
I don't actually need help with homework, but rather some advice. I'm in AP Physics B and we just finished learning torque. My teacher covered torque in just under two days and moved on to springs. Unfortunately, I was absent the first day, so I'm pretty rusty at torque. Does anyone know of a...
i'm still kind of confused...how exactly do you relate kinetic energy and momentum. I know that KE = 1/2mv^2...so does that mean you can solve v1' and v2' independly using just KE?
The value for R that I use is .08206...if that's the same that you use, you need to convert your pressure into atm's first. Then, solve for volume by doing as you said, V = 4/3 pi r^3. Once you have V, convert degrees celcius into kelvin (once again, only if your value for R is .08206...
Homework Statement
"A white pool ball (m1 = .3kg) moving at a speed of Vo1 = 3m/s collisdes head-on with a red pool ball (m2 = .4kg) initially moving at a speed of Vo2 = -2m/s. Neglecting friction and assuming the collision is perfectly elastic, what is the velocity of each ball after the...
using the energy method:
mgh = 1/2mv² + Fscosθ
(3.5kg)(10m/s²)(5.2m) = 1/2(3.5kg)(v²) + ((.3)(3.5kg)(10m/s²)(cos60))(6m)(cos0)
work that out and...
v = 9.2 m/s
Thanks for you help Doc Al. We're just beginning conservation of energy, so this is still a little bit new to me. But thanks for...
I see what you mean. So let's see, if I were to use what i previously solved (acceleration) and were to do this problem using kinematics, I'd get:
x = v0t + ½ at²
(6m) = 1/2(7.16m/s²)t²
t = 1.29s
then:
v = vo + at
v = 0m/s + (7.16m/s²)(1.29s)
v = 9.2m/s
Homework Statement
"A block of mass 3.5kg slides down an inclined plane of length 6m that makes an angle of 60° with the horizontal. The coefficient of kinetic friction between the block and the incline is 0.3. If the block is released from rest at the top of the incline, what is its speed at...
Actually, I just realized that I could've solved for x by adding 1 to the left and right, and dividing by 2 to the left and right...which gives me an answer of 3 < x ≤ 8...i'm pretty sure that's right...guess i went about it the wrong way
In interval notation, I was asked to solve for 5 < 2x - 1 ≤ 15
I did this by making the 4 cases...
2x-1>5 or 2x-1<-5 AND 2x-1≤ 15 and 2x-1≥-15
x > 3 or x < -2 AND x ≤ 8 and x ≥ -7
So for my final answer...i got [-7,-2),(3,8]
But when i check it, none of the numbers between -7 and...