Let l = Q/L = linear charge density. The semi-circle has a length L which is half the circumference of the circle. So w can relate the radius of the circle to L by
<span>C = 2L = 2*pi*R ---> R = L/pi </span>
<span>Now define the center of the semi-circle as the origin of coordinates and define a as the angle between R and the x-axis. </span>
<span>we can define a small charge dq as </span>
<span>dq = l*ds = l*R*da </span>
<span>So the electric field can be written as: </span>
<span>dE =kdq*(cos(a)/R^2 I_hat + sin(a)/R^2 j_hat) </span>
<span>dE = k*I*R*da*(cos(a)/R^2 I_hat + sin(a)/R^2 j_hat) </span>
<span>E = k*I*(sin(a)/R I_hat - cos(a)/R^2 j_hat) </span>
<span>E = pi*k*Q/L(sin(a)/L I_hat - cos(a)/L j_hat)</span>
Answer:
Explanation:
Electric field between plates
V / d
= 170 / ( 2 x 10⁻² )
= 8500 N/C
Force on electron in this field
= 8500 x 1.6 x 10⁻¹⁹
= 13600 x 10⁻¹⁹ N
Acceleration
= 13600 x 10⁻¹⁹ / 9.1 x 10⁻³¹
a = 1494.5 x 10¹² m /s²
s = .1 x 10⁻² m
v² = u² + 2as
= (2.9x 10⁵)²+ 2 x 1494.5 x 10¹² x .1 x 10⁻²
= 8.41 x 10¹⁰ + 299 x 10¹⁰
= (8.41 + 299 ) x 10¹⁰
v = 17.53 x 10⁵ m /s
To answer this question, it helps enormously if you know
the formula for momentum:
Momentum = (mass) x (speed) .
Looking at the formula, you can see that momentum is directly
proportional to speed. So if speed doubles, so does momentum.
If the car's momentum is 20,000 kg-m/s now, then after its speed
doubles, its momentum has also doubled, to 40,000 kg-m/s.
If it’s loud enough for your family to hear it, it’s best you turn it down. It could cause permanent damage to your ear drums if it’s loud enough and you could start to lose your hearing. So if your family were to tell you to turn it down, you should probably just turn it down!
