Explanation:
It is given that,
Mass of the ball, m = 1 lb
Length of the string, l = r = 2 ft
Speed of motion, v = 10 ft/s
(a) The net tension in the string when the ball is at the top of the circle is given by :



F = 18 N
(b) The net tension in the string when the ball is at the bottom of the circle is given by :



F = 82 N
(c) Let h is the height where the ball at certain time from the top. So,


Since, 

Hence, this is the required solution.
There are two possible answers:
<span>- it can move out to a higher electron shell
- </span><span> it can stay in its original shell
</span><span>
In fact, sunlight consists of photons. When sunlight hits an electron, the electron can absorbs a photon, so it gains energy: as a result, the electron can move to a higher electron shell, which corresponds to a high energy level in the atom, if the energy given by the photon is at least equal to the energy difference between the two levels. However, if the photon energy is not large enough, the electron will stay in the same shell.</span>
The sentence can be completed as follows:
<span>The motion of an object moving with uniform circular motion is always tangential to the circle, so the speed of an object moving in a circle is known as tangential speed.
The object moves by uniform circular motion due to the presence of a force (called centripetal force) pointing toward the center of the circle. Due to the presence of this force, the object experiences an acceleration (called centripetal acceleration) that makes the object turning in a circle. This centripetal acceleration changes only the direction of the velocity of the object, not its magnitude, which is called tangential speed and it is constant.</span>
Answer:
The options are approximations of the exact answers:
A) 
B) 
C) 
D) Toward the inner wall
E) 
Explanation:
A) The electric field in a parallel plate capacitor is given by the formula
, where
and in our case
and, for air,
, so we have:

B) The K+ ion has one elemental charge excess, so its charge is
, and the force a charge experiments under an electric field E is given by F=qE, so we have:

C) The potential difference between two points separated a distance d under an uniform electric potential E is given by
, so we have:

D) The electic field goes from positive to negative charges, so it goes towards the inner wall.
E) The work done by an electric field through a potential difference
on a charge Q is
, and is equal to the kinetic energy imparted on it, so we have:

Explanation:
It is given that,
Magnetic field, B = 0.1 T
Acceleration, 
Charge on electron,
Mass of electron,
(a) The force acting on the electron when it is accelerated is, F = ma
The force acting on the electron when it is in magnetic field, 
Here, 
So, 
Where
v is the velocity of the electron
B is the magnetic field


v = 341250 m/s
or

So, the speed of the electron is 
(b) In 1 ns, the speed of the electron remains the same as the force is perpendicular to the cross product of velocity and the magnetic field.