Answer:
the train stopped for 3 seconds
Explanation:
Answer: D
X-rays generally have high energy and a high frequency.
Explanation:
High-energy X-rays or HEX-rays are very hard X-rays, with typical energies of 80–1000 keV (1 MeV), about one order of magnitude higher than conventional X-rays (and well into gamma-ray energies over 120 keV).
Radio waves have much longer wavelengths and lower frequencies than do visible light waves. In contrast, X-rays have much shorter wavelengths and higher frequencies. Likewise, red light has a longer wavelength than blue light. We can also think of light as consisting of particles or packets on information that we call photons.
Answer:
The elevator is not a inertial frame of reference.
Explanation:
Lets take load = W
The tension in the string =T
T= (1-0.1 )W
T=0.9 W
From Newtons second law
If elevator move up :
T- W = ma
T= W+ ma
It means that Tension is more than the W .But given that tension is 10% less than W.
If elevator move down:
W- T = m a
T= W - m a
Yes it is true.It means that elevator is moving downward.
So we can say that the elevator is not a inertial frame of reference.
Answer:
P.E = 0.068 J = 68 mJ
Explanation:
First we need to find the height attained by the ball toy. For this purpose, we will be using 3rd equation of motion:
2gh = Vf² - Vi²
where,
g = -9.8 m/s² (negative sign due to upward motion)
h = height attained by the ball toy = ?
Vf = Final Velocity = 0 m/s (since it momentarily stops at the highest point)
Vi = Initial Velocity = 3 m/s
Therefore,
2(-9.8 m/s²)h = (0 m/s)² - (3 m/s)²
h = (9 m²/s²)/(19.6 m/s²)
h = 0.46 m
Now, the gravitational potential energy of ball at its peak is given by the following formula:
P.E = mgh
P.E = (0.015 kg)(9.8 m/s²)(0.46 m)
<u>P.E = 0.068 J = 68 mJ</u>
Answer: Potential difference
Explanation:l Let me explain
According to my understanding potential difference is always between two points. It is work done in moving a charge from one point to another
V=W/q
This PD of a charge would be work done in moving it from one place to another.
Hope this helps
