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Questions in physics

[Done] The Earth exerts a force of 1.00 newtons on an object in free fall. What is the object's mass?

[Done] A 60-watt light bulb uses 60 joules of electrical energy every second. However, only 6 joules of electrical energy is converted into light energy each second. a. What is the efficiency of the light bulb? Give your answer as a percentage. b. What do you think happens to the "lost" energy? 19. The work output is 300 joules for a machine that is 50% efficient. What is the work input? 20. A machine is 75% efficient. If 200 joules of work are put into the machine, how much work output does it produce?

[Done] A power station burns 75 kilograms of coal per second. Each kg of coal contains 27 million joules of energy. a. What is the total power of this power station in watts? (Watts = Joules/second) b. The power station’s output is 800 million watts. How efficient is this power station?

[Done] An automobile engine is 15 percent efficient. How many joules of input work are required to produce 15,000 joules of output work to move the car?

[Done] What are two different units that represent work?

[Done] 216 joules of energy is required to raise the temperature of aluminum from 15 degrees Celsius to 35 degrees Celsius. Calculate the mass of aluminum. Note: The specific heat capacity of aluminum is [tex]9.2 \times 10^2 \, \text{J/kg} \cdot \text{°C}[/tex].

[Done] A rock at the edge of a 200-meter high cliff has less potential energy than an equal-sized rock at the edge of a 600-meter high cliff.

[Done] Why does diving 30 meters below sea level affect our bodies more than being in a building 30 meters above sea level?

[Done] Convert the names below into formulas in an equation, then balance the equation. 1.) Aluminum bromide plus chlorine yields aluminum chloride plus bromine. 2.) Sodium phosphate plus calcium chloride yields calcium phosphate plus sodium chloride.

[Done] Why is the support force on an object often called the normal force?