The ideal concept for solving this question is based on the Doppler effect, for which it is indicated that the source's listening frequency changes as the distance and the relative speed between the receiver and the transmitter are also changed. However, if the relative velocity between the two objects is zero as in the particular case presented (since both travel at 75km / h) we have that there will be no change in frequency.
Therefore the frequency that I hear and that my sister would listen would be the same.
Answer:
Yeah, it can be diffracted. Though it depends on a diffracting medium.
It must have some magnetic fields .
Forexample; X-ray diffraction where electrons are diffracted to the target filament.
'D' would do the job ... When you subtract the protons from the mass,
what you have left is neutrons. (The electrons can be ignored. It takes
around 1840 electrons ! to add the mass of a single proton or neutron !)
I don't know it for a fact, but I'd be surprised if the process is really that
simple. I mean, it starts out with knowing the atomic mass, and then
knowing the number of protons in the nucleus. Each of those is a
whole complex problem in itself.
Answer:
We are Given:
initial velocity (u) = 0m/s
final velocity (v) = 25 m/s
time (t) = 10 seconds
acceleration (a) = a m/s/s
From the first equation of motion, we know that:
v = u + at
solving for a, we get:
a = (v-u) / t
now, plugging the given values in this equation
a = (25 - 0) / 10
a = 25 / 10
a = 2.5 m/s/s
Therefore, the acceleration of the car is 2.5 m/s/s
Take the upward and to-the-right directions to be positive (so down and to-the-left are negative).
The vertical forces acting on the object cancel, 6 N - 6 N = 0.
The horizontal forces exert a net force of 20 N - 3 N = 17 N. This net force is positive, so it points to the right. So the answer is A.