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A car travelling at 28 m/s brakes until it stops completely after travelling a distance of 15 m. Calculate the deceleration of the car.

· Firstly, we need to note down what we have: distance travelled, s =15 m; initial velocity, u = 28 ms^-1; final velocity, v = 0 because the car comes to rest; we are looking for the dece...

Answered by Oluyomi S. • Physics tutor

3750 Views

A student studied how a few parameters of the electromagnetic radiation affects the I-V(current-voltage) curve of photoelectricity. By increasing one parameter he saw that the saturation current has risen. Which parameter it was?

The saturation in the I-V curve is reached when the maximum number of photo-electrons generated by the light reach the electrode and we know that photocurrent is described by I=N*e/t, where N is the numbe...

Answered by Lukas S. • Physics tutor

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How would our Sun's luminosity change if we increased its temperature 3 times?

The luminosity of our Sun could be derived by the Stefan-Boltzmann, otherwise known as Luminosity law. It says the total energy produced by a unit surface per unit time area (power per unit area) is:

Answered by Denislav G. • Physics tutor

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A bungee jumper of mass 160kg falls from a cliff. The bungee cord has a natural length of 5.0m and a stiffness constant of 3.0N/m. The air resistance is a constant force of 4.0N, what's the speed of the jumper when the total length of cord is 5.9m?

This is an example of an energy consideration problem involving work done in the context of a Hooke's law situation. Firstly draw a diagram to show what's going on. Then recall that the <...

Answered by Caspar P. • Physics tutor

1634 Views

Two trains are heading in opposite directions on the same track. Train X has a mass of 16000kg and a speed of 2.8m/s. Train Y has a mass of 12000kg and a speed of 3.1m/s. At what speed do the joined trains move off together immediately after the collison?

Remembering that if the velocities are in different directions they have different signs:Total momentum before=Total momentum afterMomentum=mass x velocityTotal momentum before= (16000x2.8)+(12000x(-3.1))...

Answered by Carys J. • Physics tutor

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