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an air conditioner removes heat steadily form a house at a rate of 850 kj/min while drawing electric power at a rate of 6 kW. determine the COP of this air conditioner
a steam power plant with a power output of 250 MW consumes coal at a rate of 60 tons/h. If the heating value of the coal is 30,000 kj/kg, determine the overall efficiency of this plant
A 300N wagon is pulled up a 30° incline at constant speed.
a. How large a force parallel to the incline is needed if friction effects total of 10N?
b. What will be the force exerted by the incline to support the wagon?
c. What is the coefficient of friction?
A large wrecking ball is held in place by 2 light steel cables. If the tension Ta in the
horizontal cable is 580N,
a. What is the tension Tb in the cable that makes an angle of 40° with the vertical?
b. What is the mass of the wrecking ball?
A framed painting weighs 30kg. The two wires supporting it makes an angle of 120° with
each other. What are the tensions in the wire?
The mass of an object is
a. equal to its weight on the surface of the Earth
b. equal to its weight in deep space
c. never equal to its weight
d. sometime equal to its weight
An object moves from x1=-50cm to x2 = 30cm. What is the displacement of the object?
Water flowing along a horizontal pipe has a speed of 2.27 m/s and a pressure of 4.86 atm. Further along, the pipe narrows so that the cross-sectional area decreases by a factor of 6.44. What is the pressure in the narrow section?
Water flowing along a horizontal pipe has a speed of 2.27 m/s and a pressure of 4.86 atm. Further along, the pipe narrows so that the cross-sectional area decreases by a factor of 6.44. What is the pressure in the narrow section?
(a) Show that its height h above the ground at time t seconds is given by h = (30t - 5t^2)m. Hence or otherwise find:
(b) the maximum height reached by the ball above the level of projection.
(c) the time of flight.
