Answer:
Static friction is what keeps the box from moving without being pushed, and it must be overcome with a sufficient opposing force before the box will move. Kinetic friction (also referred to as dynamic friction) is the force that resists the relative movement of the surfaces once they're in motionExplanation:
#if you need any questions answered within mins/secs hit me up and I got you
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Answer:
1.6 x 10^-5 T
Explanation:
i = 4 A
r = 0.05 m
The magnetic field due to long wire at a distance r is given by

B = 10^-7 x 2 x 4 / 0.05
B = 1.6 x 10^-5 T
Answer:
A
Explanation:
I only think its A because of the gravity part...sorry im not good at explaining
Answer:

Explanation:
Take at look to the picture I attached you, using Kirchhoff's current law we get:

This is a separable first order differential equation, let's solve it step by step:
Express the equation this way:

integrate both sides, the left side will be integrated from an initial voltage v to a final voltage V, and the right side from an initial time 0 to a final time t:

Evaluating the integrals:

natural logarithm to both sides in order to isolate V:

Where the term RC is called time constant and is given by:

V = f x wavelength
V = 5 x 10
V = 50m/s