Q1. The diagram shows a helicopter being used to rescue a person from the sea.
(a)
(i)
The mass of the rescued person is 72 kg.
Use the equation in the box to calculate the weight of the rescued person.
gravitational field strength = 10 N/kg
Show clearly how you work out your answer. . .
Weight = .N
An electric motor is used to lift the person up to the helicopter. The motor lifts the person at a constant speed.
State the size of the force, T, in the cable.
Force T = .N

In the image, the arrow is pointing to a celestial object. which attribute disqualifies the object from being a planet?

Aheat engine running backward is called a refrigerator if its purpose is to extract heat from a cold reservoir. the same engine running backward is called a heat pump if its purpose is to exhaust warm air into the hot reservoir. heat pumps are widely used for home heating. you can think of a heat pump as a refrigerator that is cooling the already cold outdoors and, with its exhaust heat qh, warming the indoors. perhaps this seems a little silly, but consider the following. electricity can be directly used to heat a home by passing an electric current through a heating coil. this is a direct, 100% conversion of work to heat. that is, 19.0 \rm kw of electric power (generated by doing work at the rate 19.0 kj/s at the power plant) produces heat energy inside the home at a rate of 19.0 kj/s. suppose that the neighbor's home has a heat pump with a coefficient of performance of 4.00, a realistic value. note: with a refrigerator, "what you get" is heat removed. but with a heat pump, "what you get" is heat delivered. so the coefficient of performance of a heat pump is k=qh/win. an average price for electricity is about 40 mj per dollar. a furnace or heat pump will run typically 200 hours per month during the winter. what does one month's heating cost in the home with a 16.0 kw electric heater? what does one month's heating cost in the home of a neighbor who uses a heat pump to provide the same amount of heating?

Which lists the pairs of plates in order from least to greatest in terms of the work done to move the electron?