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A 1000kg car accelerates from 0 to 20 m/s in 15 seconds. Calculate the acceleration of the car, the force required for this acceleration and the momentum of the car at 20 m/s.

The first part of the question, calculating the acceleration, uses the fact that acceleration equals the change in velocity divided by the time. In this case, the change in velocity is 20-0 and the time is 1...
RM
Answered by Richard M. • Physics tutor
5328 Views

A 100kg weight is placed 0.75 meters from a see-saw on the right hand side. Dan is 75kg. How far away does he have to sit from the pivot on the left hand side to have it balance?

A see-saw represents a pivot, for the see-saw to balance the moment on the left hand side has to equal the moment on the right hand side. Moment = Force * distance Therefore the moment of the right hand side...
AC
Answered by Alex C. • Physics tutor
2979 Views

Sound waves are longitudinal. Describe a longitudinal sound wave.

There are two types of wave: longitudinal and transverse. It's really important to learn their properties as this is a very common question. The main thing to remember is longitudinal waves have oscillations...
IS
Answered by Isabel S. • Physics tutor
5325 Views

Compare the advantages and disadvantages of the two methods of generating electricity (figure 1 in answer):

Figure 1 (AQA GCSE Science A Physics: Higher Tier): The wind turbine costs £50 000 to buy and install. The hydroelectric generator costs £20 000 to buy and install. The average power output from the wind tur...
CH
Answered by Charlie H. • Physics tutor
21601 Views

Why does voltage increase (for a constant current) if temperature increases?

Voltage is directly proportional to resistant (V=IR) and resistance increases with temperature due to increased vibrations of the molecules inside the conductor. Therefore voltage increases as temperature in...
AH
Answered by Annie H. • Physics tutor
62311 Views