Answer:
0.7 mJ
Explanation:
<u>Identify the unknown: </u>
The work required to turn the dial from 180° to 0°
<u>List the Knowns: </u>
Capacitance when the dial is set at 180°: C = 350 pF = 350 x 10^-12 F Capacitance when the dial is set at 0°: C = 100 pF = 100 x 10^-12 F
Voltage of the battery: V = 130 V
<u>Set Up the Problem:</u>
<em><u>Energy stored in a capacitor: </u></em>
U_c=1/2*V^2*C
=1/2*Q^2/C
<em><u>When the dial is set at 180°:</u></em><em> </em>
U_c=1/2*(130)^2*350*10^-12=10^-4
Q=√2*U_c*C=4*10^-7
<u><em>When the dial is set at 0°:</em></u>
U_c=1/2*(4*10^-7)^2/100*10^-12
=8*10^-4 J
<u><em>Solve the Problem: </em></u>
ΔU_c=7*10^-4 J
=0.7 mJ
note:
there maybe error in calculation but method is correct
Net force = 50 + 50 = 100 M
Since two forces act towards the same direction , total force should be their sum amd towards the same direction as the two forces
The two correct statement are A and B. Light waves are electromagnetic waves that can travel through a vacuum. Mechanical waves can travel through a vacuum.
<h3>What is an electromagnetic wave?</h3>
EM waves are the electromagnetic radiations are made up of electromagnetic waves created when an electric field collides with a magnetic field.
Electromagnetic waves may alternatively be defined as the combination of oscillating electric and magnetic fields.
Electrically charged particles experiencing acceleration create electromagnetic waves, which can then interact with other charged particles and exert force on them.
The two correct statement is;
1. Light waves are electromagnetic waves that can travel through a vacuum.
2. Mechanical waves can travel through a vacuum.
Hence,two correct statement are A and B.
To learn more about the electromagnetic wave refer to the link;
brainly.com/question/8553652
#SPJ1
The speed for a curve of a given radius is proportional to the square root of the coefficient of static friction. The allowed speed in the second curve is about
(20 m/s)√(0.7/1.1) ≈ 15.95 m/s