An object of mass m=5kg is being pulled up an inclined plane which is at 40° to the horizontal. The object is pulled at a constant speed of 0.8ms-1 by a force which acts parallel to the inclined plane.
The coefficient of friction between the object and the plane is 0.2
a)Draw a diagram showing the forces acting on the object.
b)Calculate the magnitude of the force of friction acting on the object.
c)Calculate the gain in gravitational potential energy when the object has moved 0.5m (measured parallel to the slope).
d)Calculate the total work done in pulling the block 0.5m (measured along the slope).​

Awoman holds a book by placing it between her hands such that she presses at right angles to the front and back covers. the book has a mass of m = 1.8 kg and the coefficient of static friction between her hand and the book is μs = 0.67. no attempt 50% part (a) what is the weight of the book, fgb in newtons?

Aresistor with an unknown resistance is connected in parallel to a 9 ω resistor. when both resistors are connected in parallel to an emf source of 21 v, the current through the unknown resistor is measured with an ammeter to be 4 a. what is the resistance of the unknown resistor? answer in units of ω.

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)