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An apple is suspended a string and a spring in parallel. When the string is cut, the apple falls, and the spring stretches and contracts repeatedly as the apple bounces. Describe the energy conversions that occur during this process.

When the string is cut:Gravitational potential energy is converted to kinetic energy.Kinetic energy is converted to elastic potential energy.Elastic potential energy is converted to kinetic energy (and heat ...
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Answered by Dan S. • Physics tutor
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Explain what terminal velocity means.

Consider an object in free fall through the atmosphere. Firstly, we need to consider the forces acting on the object. A force diagram will help here. Weight acts from the centre of mass of the object towards...
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Answered by Alex M. • Physics tutor
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An electric whisk in a bakery has two motors, each with an average power of 1500W. The whisk is used for 4 hours each day, 7 days a week. Electricity costs 18p per kilowatt-hour. Calculate the cost of the electricity used by the whisk in one week.

First, we must calculate the amount of time spent using the whisk in one week:4 x 7 = 28 hours a weekNext we calculate the power used; as the whisk has two motors, the average power used by the whole whisk i...
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Answered by Iqra S. • Physics tutor
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What are the 3 main types of radiation?

The three main types of radiation are alpha, beta and gamma radiation. Alpha particles are the largest, two protons and two neutrons bound together (so they have a +2 positive charge). They are the most ioni...
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Answered by Sarah A. • Physics tutor
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A car of mass 1000 kg is travelling at 15 m/s. The driver applies the brakes for 4 seconds, slowing the car to 5 m/s. What is the average power output of the brakes over the 4 seconds? Assume there are no other forces acting on the car.

Kinetic Energy, EK=(1/2)mv 2 . Energy is conserved, so the work done by the brakes, W, must be equal to the change in kinetic energy of the car, ∆EK. Therefore: W = ∆EK = (1/2) 1000 (15 2 -5 2 ) = 0.5 1000 2...
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Answered by Adam H. • Physics tutor
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