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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)mv². 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

Answered by Adam H. • Physics tutor

8929 Views

i) The point A on a graph is (6,-7), and point B is (3,5). Calculate the equation of the straight line that passes through both A and B. ii) Does the line pass through the point C (-2,26)?

i) Gradient (m) = ∆y/∆x. Therefore: m = (5-(-7))/(3-6) = (12)/(-3) = -4. Intercept (c) = 5-(3*(-4)) = 5+12 = 17. Therefore: y = -4x+17 ii) x = -2, y = 26. -4(-2) + 17 = 25. 25≠26, therefore the line does ...

Answered by Adam H. • Maths tutor

2763 Views

How are is consumer and producer suplus shown on a diagram of supply and demand? How are both the division and amount of total surplus determined?

Starting with the curves themselves, we have a downward sloping demand curve as more people are willing to buy at lower prices. Conversely, seller will be willing to offer more goods for sale as the price...

Answered by Joshua L. • Economics tutor

1605 Views

How can I improve my overall fluency and the ease at which I am able to speak and understand French?

The greatest advice I could give would be to just immerse yourself, read, listen and speak as much as possible- use every opportunity that arises and search for those which are less visible and will push ...

Answered by Kate P. • French tutor

1602 Views

How is DNA replicated?

DNA replication starts at an origin - eukaryotic chromosomes have multiple origins whereas prokaryotic chromosomes have only one. Here an enzyme called helicase separates the existing ("parental"...

Answered by Sarah A. • Biology tutor

2748 Views