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A 1,200 kg car ascends a road inclined at 200 to the horizontal at 25 km/h. Neglecting frictional opposition, estimate the power required to keep going at this speed.
A power station delivers 25 MW of electrical power. How many tonnes of fuel oil would be needed by this station to deliver the 25 MW of power for 1 month of 30 days, assuming a conversion efficiency of 34%. (1 tonne of oil equivalent in energy = 4.2 X 1010 J, 1 tonne = 1,000 kg).
Discuss two ways each in which fossil fuel energy can be conserved in Caribbean homes through:
a) measures involving reduced wastage of energy
b) sensible choice of equipment and appliances
c) making use of renewable energy.
It is planned to have replaced 20 MW output from a fossil fuel power station with a 20 MW output solar-voltaic power station. If the average solar insolation (power incident normally per square metre on the surface of the Earth) at a given location is 350 W m-2, and the efficiency of the solar-voltaic cells is 20%, estimate the area of land surface required for generating the 20 MW of electrical power using solar-voltaic panels.
A 24-N horizontal force is applied to a 40-N block initially at rest on a rough horizontal surface. If the coefficients of friction are µs = 0 .5 and µk = 0 .4, find the magnitude of the frictional force on the block.
A 200 kg load is hung on a wire having a length of 4 m, cross-sectional area 1.2 x10-4 m2 , and Young‘s modulus 8 x 1010 N/m2 . What is its increase in length?
A particle P is projected from a point O with an initial velocity of 70m/s at an angle 30° to the horizontal. At the same instant a second particle Q is projected in the same direction, 20m from point O with initial speed 25m/s from a point level with O. If Particle Q is displaced to 90m from point of release C. If the particles Q collide with P at 80m from the point of release C, find the angle of projection of Q and find when the collision occurs.
A particle P is projected from a point I with an initial velocity of 70m/s at an angle of 30° to the horizontal. At the same instant, a second particle Q is projected in the same direction, 20m from point I with initial speed 25m/s from a point level with O. If particle Q is displaced to 90m from point of release C. If the particle Q collides with P at 80m from the point of release C, find the angle of projection of Q and find when the collision occurs.
In a cheerdancing competition, a 65.0 kg cheerleader is tossed vertically upward
with a speed of 3.75 m/s. a) what is the initial momentum of the cheerleader at
the moment she was tossed up? b) what is her momentum just before being
caught, assuming she was caught at the same height? c) what is the change in
momentum of the cheerleader?
A boy stands still in a weighing Machine which then read 65kg,he jumps upwards at the instant just before he jumps the machine reads 85kg.what acceleration does he acquire?
