If committees is an option it is the correct one.
Answer:
A. 5 m/s
Explanation:
From the graph, for the first 2 seconds, the graph is a straight line meaning that the slope is a constant.
Average speed of an object is the rate of change of position. Here, the position of the object changes from 0 m to 10 m for a time interval of 2 seconds.
The change in position () and time interval () are given as:
Therefore, the average speed () is given as the ratio of the total change in position and the time interval for the change.
Hence, the average speed is 5 m/s.
Answer:
Explanation:
First of all, let's calculate the energy of a single photon of wavelength
which is given by
The power of the flash is
and the time it lasts is
so the total energy delivered in one flash is
This energy contains exactly N photons each of energy , so the number of photons emitted in one flash is
There are a lot of same examples that you may have worked before, where the mass on a spring uses a classics when it comes to mechanics. So in this system, always put in your mind that there is an enormous quantum standard that one can use in the equation. It should be 2.10x10 raise to a negative sixth. J.