Homework Statement
Princeton p 411 #6
A 7 kg ball is dropped from 20m. if the speed just before it hits the ground in 18 meters per second, what is the work done by air resistance?[/B]Homework Equations
KE= (mv^2)*1/2
PE=mgh[/B]The Attempt at a Solution
Mgh equals 1400 joules. PE equals...
Im sorry. The correct circumference in the problem is 0.5 m. So circumference calculation is correct. But the answer isn't off by a degree of 10 anyway :-(
Homework Statement
P62 Sterling. #11
A new design for a car is to have a large disc like flywheel within the car storing kinetic energy. The flywheel has a mass of 370 kg witha radius of 0.5 meters and can rotate up to 200 revolutions a second. Assuming all of this store kinetic energy can be...
Homework Statement
If the height of a frictionless incline is h. Determine the work done by the force due to gravity F as the crate of the mass m slides down the incline
Homework Equations
W=Fd cos (theta )
Force due to gravity perpendicular to incline= mg cos(theta)
The Attempt at a...
if you are in a helicopter and something in the air, when it reaches as high as it will go, it's Vertical Velocity will be zero. That is the distance from the helicopter
Oh my gosh
You're right, I was calculating the wrong distance! I figured out what I was doing wrong. Thank you so much for...
Homework Statement ( p 49 sterling)
Ignoring air resistance, if it takes 16 seconds for a package to strike the ground, how high above the ground was a package when it was thrown upward from the stationary helicopter at 15 m/s per second[/B]Homework Equations
V=Vo+at
D=Vot+(1/2)at^2
The Attempt...