So there are different ways this could be solved. I'll do try to explain it the way I was taught...
Simon is riding his bike at 12 km/hr relative to the sidewalk, away from where Keesha is.
Simon throws the ball at Keesha, at 5 km/hr.
Keesha sees the ball approaching her at (12-5) = 7 km/hr relative to the ground to her.
Therefore the answer is: 7 km/hr
Answer:
i = 101.4A
Explanation:
The steps to the solution can be found in the attachment below.
We have been given the frequency f = 60Hz. From this we can calculate the angular frequency of the power line.
It is assumed that sinwt = –1 in order to calculate the time varying current. Although the magnitude of the current is large, consideration should also be given to the distance between the coil and the power line. The induced emf is small considering the area of the coil which is 7.85×10-⁵m².
You always multiply the mass (kg) by the velocity at which the object is travelling (m/s) to get the momentum (kg m/s) thus: 30 × 5 = 150 kg m/s