Work is done when a force acts on an object AND the object moves in the direction of the force.
-- Pulling a trailer up a hill. YES. The trailer is moving in the direction of the pulling force.
-- Carrying a box down a corridor. No. The box is not moving in the direction of gravity (down) OR in the direction of your arm (down the corridor).
-- Suspending a heavy weight with a strong chain, No. There's a force (gravity) acting on the weight, but the weight is not moving at all.
-- Pushing against a locked door. No. There's a force (your muscles) acting on the door, but he door is not moving at all.
If your taking a quiz, exam, test, etc.. the correct answer would be
(Pulling a trailer up a hill)
I took the test and I can confirm this answer is correct.
Have a great day! :)
a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm. the wire diameter is d = 0.9 mm. the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.
randomized variablesl = 90 m
d = 4.5 cm
d = 0.9 mm
i = 9 a
write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.
calculate the number of turns, n, in the solenoid.
write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.
calculate the length of the solenoid (l2) in meters.
calculate the magnitude of the magnetic field at the center of the solenoid in teslas.
pe = weightxheight = 2000x1000=2,000,000joules