Answer:
a) 60 V
b) 125 V
c) 125 V
Explanation:
<u>Given</u>
We are given the total electric charge q = 6.75 nC = 6.75x 10^-9 C distributed uniformly over the surface of a metal sphere with a radius of R = 20.0 cm = 0.020 m.
<u>Required </u>
We are asked to calculate the potential at the distances
(a) r = 10.0 cm
(b) r = 20.0 cm
(c) r = 40.0 cm
<u>Solution</u>
(a) Here, the distance r > R so, we can get the potential outside the sphere (r > R) where the potential is given by
V = q/4
∈_o (1)
r is the distance where the potential is measured and the term 1/4∈_o equals 9.0 x 10^9 Nm^2/C^2. Now we can plug our values for q and r into equation (1) to get the potential V where r = 0.10 m
V= 1*q/4∈_o*r
=60 V
(b) Here the distance r is the same for the radius R, so we can get the potential inside the sphere (r = R) where the potential is given by
V = 1*q/4∈_o*R (2)
Now we can plug our values for q and R into equation (2) to get the potential V where R = 0.20 m
V = 1*q/4∈_o*R
= 125 V
(c) Inside the sphere the electric field is zero therefore, no work is done on a test charge that moves from any point to any other point inside the sphere. Thus the potential is the same at every point inside the sphere and is equal to the potential on the surface. and it will be the same as in part (b)
V= 125 V
<span>The answer is friction. The force acting upon the comparative motion of solid surfaces, liquid layers, and material elements sliding in contradiction of each other. When sides in contact move comparative to each other, the friction amid the two surfaces changes kinetic energy into thermal energy; in other words work to heat. </span>
The 2 positively charged particles would repel each other.
Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of
Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is
with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.
Force = 0.20N .F = m ×a .& a = v/t then the f = m×v/t
