Top answers

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 deceleration hence a; s...
OS
Answered by Oluyomi S. • Physics tutor
4385 Views

What's the difference between a vector and a scalar?

A scalar is a single quantity giving an "amount" of something - it only has a magnitude. For example, temperature or energy are represented by a single value. On the other hand, a vector has both m...
JC
Answered by Jasmine C. • Physics tutor
4722 Views

The speed of light is 3.0 × 10^8 m/s. The wavelength of yellow light is 5.8 × 10^−7 m. Calculate the frequency of yellow light. State the unit.

We know that frequency is 1/time, thus the unit is Hz (equal to s^-1). To calculate the frequency value, we use the equation Frequency = Wavespeed (m/s) / Wavelength (m). (This also provides a checking answe...
AH
Answered by Alister H. • Physics tutor
10931 Views

Why do people not fall from the earth?

The earth is a big cube that rotates. It spins at 1.000miles per hour which is around ten times as fast as a speed car. Still we fall not of because the earth is like a magnet for human.It has a south and a ...
MF
Answered by Milena F. • Physics tutor
2436 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 number o...
LS
Answered by Lukas S. • Physics tutor
2129 Views