Which pulley setup would decrease the amount of effort force needed to lift an object

a) two fixed position pulleys attached to a fixed point above the object that's being lifted

b) one fixed position pulley attached to a fixed point above the object that is being lifted

c) no pulleys just a string attached to an object that is being lifted

d) one moving pulley attached to the object that is being lifted

Calculate the amount of heat produced when 18000 coulombs of charge is transferred in one hour through a potential difference of 50v

Mass (kg) force (n) 5 25 10 50 15 75 20 100 a student was trying to find the relationship between mass and force. he placed four different masses on a table and pulled them using a spring scale. the table shows the different masses used in the experiment and the force required to pull each mass. the student concluded that more force was required to pull heavier objects. what comment would you make regarding his conclusion? a) no clear relation can be observed between mass and force from the data. b) there is a direct proportion between the mass and force listed in the table. c) gravity should have been taken into account while performing the experiment. d) there is an inverse proportion between the mass and force listed in the table.

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.