In the figure a worker lifts a weight by pulling down on a rope with a force . The upper pulley is attached to the ceiling by a chain,and the lower pulley is attached to the weight by another chain.The weight is lifted at constant speed. Assume that the rope,pulleys, and chains all have negligible weights.
A) In terms of ,find the tension in the lower chain.
B) In terms of ,find the tension in upper chain.
C) In terms of ,find the magnitude of the force if the weight is lifted at constant speed.
A solenoid is designed to produce a magnetic field of 0.0270 T at its center. It has radius 1.40 cm and length 40.0 cm, and the wire can carry a maximum current of 12.0 A. (a) What minimum number of turns per unit length must the solenoid have? (b) What total length of wire is required?
two small spheres spaced 20.0cm apart have equal charges.How many excess electrons must be present on each sphere if magnitude of the force of repulsion betweeen them is 3.33*10-21 N