This is Kinematics and the equations in your book.
A speed time graph would plot the speed of something against the teime it was at a speed.
If it were changing it speed constantly, that would be a straight line if acclerating. Total distrance would be the area under the graph.
Answer:
The magnetic field strength needed is 1.619 T
Explanation:
Given;
Number of turns, N = 485-turn
Radius of coil, r = 0.130 m
time of revolution, t = 4.17 ms = 0.00417 s
average induced emf, V = 10,000 V.
Average induced emf is given as;
V = -ΔФ/Δt
where;
ΔФ is change in flux
Δt is change in time
ΔФ 
where;
N is the number of turns
B is the magnetic field strength
A is the area of the coil = πr²
θ is the angle of inclination of the coil and the magnetic field,
V = NBACos0/t
V = NBA/t
B = (Vt)/NA
B = (10,000 x 0.00417) / (485 x π x 0.13²)
B =1.619 T
Thus, the magnetic field strength needed is 1.619 T
Answer:
+1.46×10¯⁶ C
Explanation:
From the question given above, the following data were obtained:
Charge 1 (q₁) = +26.3 μC = +26.3×10¯⁶ C
Force (F) = 0.615 N
Distance apart (r) = 0.750 m
Electrical constant (K) = 9×10⁹ Nm²/C²
Charge 2 (q₂) =?
The value of the second charge can be obtained as follow:
F = Kq₁q₂ / r²
0.615 = 9×10⁹ × 26.3×10¯⁶ × q₂ / 0.750²
0.615 = 236700 × q₂ / 0.5625
Cross multiply
236700 × q₂ = 0.615 × 0.5625
Divide both side by 236700
q₂ = (0.615 × 0.5625) / 236700
q₂ = +1.46×10¯⁶ C
NOTE: The force between them is repulsive as stated from the question. This means that both charge has the same sign. Since the first charge has a positive sign, the second charge also has a positive sign. Thus, the value of the second charge is +1.46×10¯⁶ C
