Hy does the efficiency of simple machine increase when oil or grease is used carpet is beaten with a stick to remove the dust particles. Why?
Thy is the unit of power called derived unit?
Group
Group 'D'
4*4=16
13. A boy of mass 40 kg runs upstairs and reaches the 8 m high first floor
seconds. Calculate.
a. The force of gravity acting on the boy.
b. The work done by him against gravity.
c. The power of the boy.
bability and sketch the solubility carve of sodium chlorid​

A2k pendulum has a speed of 1 m/s at a height of 1/2 meter

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)

Aball thrown by ginger is moving upward through the air. diagram a shows a box with a downward arrow. diagram b shows a box with an upward arrow. diagram c shows a box with a downward and upward arrow equal in size. diagram d shows a box with a downward and upward arrow with the downward arrow larger in size. which force diagram represents the forces on the ball? you may neglect the effects of air resistance.