Answer:
<em>The tension force of the cable is 588 N</em>
Explanation:
<u>Net Force</u>
The Second Newton's law establishes that the acceleration an object has depends on the net force through the equation:
F = m.a
If the net force is zero, then the acceleration is zero, and the object's velocity remains constant.
The crane lifts a 60 Kg load at a constant velocity. It means the net force acting on the load is zero.
There are two forces acting on the load: The weight of the load and the tension of the cable that holds it.
Since the net force is zero, both forces have the same magnitude:
![T = m.g = 60\ kg\cdot 9.8\ m/s^2](https://tex.z-dn.net/?f=T%20%3D%20m.g%20%3D%2060%5C%20kg%5Ccdot%209.8%5C%20m%2Fs%5E2)
T=588 N
The tension force of the cable is 588 N
The answer is 9.8 ms^-2, because there is only one force acting on the object so the acceleration will be numerically equal to the gravitational field strength.
To calculate the value of unknown charge, we use the formula the electric force between two charges
![F=\frac{1}{4\pi \epsilon_{0} }\frac{Qq}{r^2}](https://tex.z-dn.net/?f=F%3D%5Cfrac%7B1%7D%7B4%5Cpi%20%5Cepsilon_%7B0%7D%20%20%7D%5Cfrac%7BQq%7D%7Br%5E2%7D)
Here, q is unknown charge ,
,
and ![\frac{1}{4\pi \epsilon_{0} } = k= 8.988 \times 10^9 Nm^2/C^2](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%5Cpi%20%5Cepsilon_%7B0%7D%20%20%7D%20%3D%20k%3D%208.988%20%5Ctimes%2010%5E9%20Nm%5E2%2FC%5E2)
Now substituting the given values in above formula we get
![0.600 N= 8.988 \times 10^9 Nm^2/C^2 ( \frac{-0.590 \mu C \times q}{(0.300)^2}](https://tex.z-dn.net/?f=0.600%20N%3D%20%208.988%20%5Ctimes%2010%5E9%20Nm%5E2%2FC%5E2%20%28%20%5Cfrac%7B-0.590%20%5Cmu%20C%20%5Ctimes%20q%7D%7B%280.300%29%5E2%7D)
or
![q = 10.1 \mu C](https://tex.z-dn.net/?f=q%20%3D%2010.1%20%5Cmu%20C)
The unknown charge is positive because the force between charges is attractive.
Answer:
3. both are true.
Explanation:
Energy increses with decrease in wavelenght.
For photoemission to occur, a threshold energy barrier must be broken.
Higher energy means more electrons will be emmited.
The electrons emmited will posses energy that is less than the incident energy by the value of the threshold energy.
So the higher the energy, the higher the energy possessed by the electrons.