PLEASE HELP ME WITH THOSE 3 QUESTIONS 1) A motor outputs 1000 J of energy in a given amount of time. 100 J is used to turn a rotor. How much heat energy is gained by the air around the engine?

2) A virtual image is 3 meters behind a flat mirror and it is 2 meters tall. What is the height and distance from the mirror, for the object?

3) A concave mirror has a focal length of 1 meter. An object is 2 meters from the mirror. What is the image distance from the mirror?

The magnitude of the amount of energy released by burning a fuel source, measured in energy per unit mass, is called its fuel value. note that the fuel value is the negative of the isobaric specific heat of combustion for the fuel. if all the energy obtained from burning 1.23 pounds of butane with a fuel value of 10.85 kcal/g is used to heat 128.0 kg of water at an initial temperature of 18.3 °c, what is the final temperature? note that 1 lb = 453.6 g.

An object dropped from cliff falls with a constant acceleration of 10 metre per second square find its speed of two seconds after it was dropped

Aleaky 10-kg bucket is lifted from the ground to a height of 15 m at a constant speed with a rope that weighs 0.7 kg/m. initially the bucket contains 45 kg of water, but the water leaks at a constant rate and finishes draining just as the bucket reaches the 15-m level. find the work done. (use 9.8 m/s2 for g.) show how to approximate the required work by a riemann sum. (let x be the height in meters above the ground. enter xi* as xi.) lim n → ∞ n (9.8)(45−3 xi) i = 1 δx express the work as an integral. 0 dx evaluate the integral. (round your answer to the nearest integer.) j