Question
explain
When an autornobile moves with constant speed down a highway, most of the power developed by the engine is used to compensate for the mechanical energy loss due to frictional forces exerted on the car try by the air and the road. If the power developed by the engine is 170 hp, estimate the total friction force acting on the car when it is moving at a speed of 23 m/s. One horsepower equals 746 W. An energy-efficient lightbulb, taking in 26.0 W of power, can produce the same level of brightness as a conventional lightbulb operating at power 100 W. The lifetime of the energy-efficient bulb is 10 000 h and its purchase price is $4.70, whereas the conventional bulb has lifetime 750 h and costs $0.60 per bulb. Determine the total savings obtained by using one energy-efficient bulb over its lifetime as lifetime as opposed to using conventional bulbs over the same time period. Assume an energy cost of $0.20 per kilowatt-hour.
Explanation / Answer
Power = 170 hp = 170 x 746 W =126820 W
Power = F.v
126820 = F x 23
F = 5513.91 N ........Ans
Please One question in single link.
