Homework Statement
A ladder is made in the shape of the letter A. Treat the two sides of the ladder as identical uniform rods, each weighing 455 N, with a length of 3.60 m. A frictionless hinge connects the two ends at the top, and a horizontal wire, 1.20 m long, connects them at a distance...
Homework Statement
The picture below shows a mobile
in equilibrium. Each of the rods is 0.16m long and each hangs from a supporting string that is attached one fourth of the way across it. The mass of each rod is 0.10kg. The mass of the strings connecting the blocks to the rods is...
Homework Statement
A thin hoop of mass 7.8kg rolls on a horizontal floor with a speed (at its center of mass) of 0.23 m/s. How much work must be done on the hoop to bring it to a stop.
Homework Equations
m = 7.8kg
Vcm = 0.23m/s
KE = 1/2*m*Vcm + 1/2Iw2
I = m*r2
The Attempt...
Homework Statement
The pulley in the illustration is a uniform disk of mass 2.40 kg and radius 0.220 m. The block applies a constant torque to the pulley, which is free to rotate without friction, resulting in an angular acceleration of magnitude 0.180 rad/s2 for the pulley. As the block falls...
Homework Statement
A windmill starts from rest and rotates with a constant angular acceleration of 0.25 rad/s2. How many seconds after starting will the magnitude of the tangential acceleration of the tip of a blade equal the magnitude of the centripetal acceleration at the same point...
Homework Statement
A coin is rolled without slipping on a table top in a straight line. It starts rolling at 3.4 rad/s and slows down at a constant angular acceleration. It is rolling at 1.2 rad/s when it falls off the table edge. If the radius of the coin is 0.011m, and the edge of the...
Homework Statement
An engine supplies an upward force of 9.00N to an initially stationary toy rocket, of mass 54.0g, for a distance of 25.0m. The rocket rises to a height of 339 meters before falling back to the ground. What was the magnitude of the average force of air resistance on the...
Homework Statement
A weightlifter raises a 115kg weight from the ground to a height of 1.95m in 1.25 seconds. What is the average power of this maneuver.
Homework Equations
m = 115kg
Change in Y = 1.95m
time = 1.25 seconds
The Attempt at a Solution
V = 1.95/1.25 = 1.56 m/s
a...
Then I end up with the same answer as my second try though. Unless I'm calculating Force wrong?
Velocity = 3.96m/s
Acceleration = .396m/s2
Fy = m*a
Fy = (1.20×105) * .396m/s2
Fy = 47,520
P = F * v
P = (47520)(3.96)
P = 188179.2 watts
Homework Statement
Stuntman's Freefall, a ride at Six Flags Great Adventure in NewJersey, stands 39.6 meters high. Ignoring the force of friction, what is the minimum power rating of the motor that raises the 1.20×105kg ride from the ground to the top in 10.0 seconds at a constant velocity...
This is what I get for working after being completely mentally drained.
Ok so, it should have been 400,000 DIVIDED by 3600
which gives me 111.1111~ m/s
-> a = 111.111~ / 2.5
-> a = 44.4444~
So now I have my (correct?) acceleration. But once again I'm stuck. If I multiply the...
Homework Statement
At the Aircraft Landing Dynamics Facility located at NASA's Langley Research Center in Virginia, a water-jet nozzle propels a 46,000 kg sled from zero to 400 km/hour in 2.5 seconds. Assuming a constant acceleration for the sled, what distance does it travel during the...