<span>The photoelectric effect is about electrons being ejected from metals when light is shined on metals. The electrons do not behave like waves in the photoelectric effect. Black body radiation is all about the radiation emitted by warm bodies and not about those bodies behaving like waves. The emission spectra of atoms is all about what light is given off by atoms when electrons in those atoms jump down to lower energy levels from higher levels. That also has nothing to do with matter behaving as a wave. Interference is classically defined as the generation of a new wave with an amplitude modulated according to the waves that interfere to form that new wave. Note its emphasis on the wave part.</span>
<span> We're given that x=25 when t=2: </span>
<span>25 = 3 + 12(2) + (1/2)a(2)^2 </span>
<span>Thus a = -1 cm/sec^2</span>
Answer:
F= 600 N
Explanation:
Given that
Initial velocity ,u= 0 m/s
Final velocity ,v= 30 m/s
mass ,m = 0.5 kg
time ,t= 0.025 s
The change in the linear momentum is given as
ΔP= m (v - u)
ΔP= 0.5 ( 30 - 0 ) kg.m/s
ΔP= 15 kg.m/s
We know that from second law of Newtons


Now by putting the values

F= 600 N
a. The disk starts at rest, so its angular displacement at time
is

It rotates 44.5 rad in this time, so we have

b. Since acceleration is constant, the average angular velocity is

where
is the angular velocity achieved after 6.00 s. The velocity of the disk at time
is

so we have

making the average velocity

Another way to find the average velocity is to compute it directly via

c. We already found this using the first method in part (b),

d. We already know

so this is just a matter of plugging in
. We get

Or to make things slightly more interesting, we could have taken the end of the first 6.00 s interval to be the start of the next 6.00 s interval, so that

Then for
we would get the same
.