Missing detail in the text:
"<span>A small glass bead has been charged to + 25 nC "
Solution
The force exerted on a charge q by an electric field E is given by
</span>
<span>Considering the charge on the bead as a single point charge, the electric field generated by it is
</span>
with
,
is the charge on the bead. We want to calculate the field at
:
The proton has a charge of
, therefore the force exerted on it is
And finally, we can use Newton's second law to calculate the acceleration of the proton. Given the proton mass,
, we have
The charge on the bead is positive, and the proton charge is positive as well, therefore the proton is pushed away from the bead, so:
Answer:
Explanation:
reading of scale = reaction force of surface R
centripetal force = R - mg = m v² / R , m is mass , v is velocity and R is radius of the circular path .
R = mg + m v² / R
given ,
m v² / R = .80 mg
v² = .80 x g x R
= .8 x 9.8 x 9 = 70.56
v = 8.4 m /s
Answer:
d. 2m to the right of the pivot
Explanation:
m1 = m
m2 = 0.5m
d1 = 1m
d2 = ?
from principle of moment,
CWM = ACWM
m × 1 = 0.5m × d2
d2 = m/0.5m
= 1/0.5
= 2m
The 2nd child will have to sit 2m to the right
The turning effect of a force is known as the moment. It is the product of the force multiplied by the perpendicular distance from the line of action of the force to the pivot or point where the object will turn.
The principle of moments states that when in
equilibrium the total sum of the anti clockwise
moment is equal to the total sum of the
clockwise moment.
When a system is stable or balance it is said to be in equilibrium as all the forces acting on the system cancel each other out.
In equilibrium
Total Anticlockwise Moment = Total
Total Anticlockwise Moment = TotalClockwise Moment
Answer:
The wavelength is 173 nm.
Explanation:
This kind of phenomenon is known as photoelectric effect, it occurs when photons of light inside the metal surface and if they have the right amount of energy electrons absorb it and got expelled from the metal as photo electrons. The maximum kinetic energy of that photo electrons is given by the expression:
(1)
With E the energy of the photon and Φ the work function of the material. The work function is a value characteristic of each material and is related with how much the electron is attached to the material, the energy of the photon is the Planck's constant (h=
) times the frequency of light (
) , then (1) is:
(2)
The frequency of an electromagnetic wave is related with the wavelength (
) by:
(3)
with c the velocity of light (c=
)
Using (3) on (2):
Solving for 
:
That's the work function of the metal we're dealing. So now if we want to know the wavelength to obtain the double of the kinetic energy we use:
Solving for :
