Answer:
The answer to your question is letter A. r = 1.07 x 10⁻¹⁴ m
Explanation:
Data
F = 2 N
d = ?
q = 1.6 x 10 ⁻¹⁹ C
k = 8.987 Nm²/C²
Formula

Solve for r

Substitution

Simplification
r = 
r = 
Result
r = 1.07 x 10⁻¹⁴ m
Answer:
4. 10.0 m/s²
Explanation:
I) if initial velocity is 'v₀', the final velocity is 'v', the accelaration is 'a', the distance is 'L' and elapsed time if 't', then:


II) using these two equations after substitution v₀=0; v=30 and L=45:


Answer:
a) according to Faraday's law
, b) creating a faster movement, placing more turns on coil
Explanation:
a) The voltage is induced in the coil by the relative movement between it and the magnet, therefore according to Faraday's law
E = - d (B A) / dt
In this case, the magnet is involved, so the value of the magnetic field varies with time, since the number of lines that pass through the loop changes with movement.
This voltage creates a current that charges the battery
b) There are several ways to increase the voltage
* creating a faster movement, can be done by the user
* placing more turns on the coil, must be done by the manufacturer
The instrument would be a barometer.
It is a battery (the long and short lines represent 2 cells)