Answer:
55N
Explanation:
Using Newton's second law of motion:
F=ma
Force=mass × acceleration
F=25×2.2
F=55N
So 55 Newtons are needed
Basically, you want to take the integral of each interval and compare them. The two intervals with the same integral represent equal displacement of the particle. And since delta(x) is always 2, all you have to do is average the initial and final velocities of each interval and multiply by two to find total displacement.
Hope it helped.
Edit to show calculations:
2 * [ (0 + 10)/2 ] = 10 for interval AB
2 * [ (7 + 3)/2 ] = 10 for interval DE
Answer:
The dynamo has a wheel that touches the back tyre. As the bicycle moves, the wheel turns a magnet inside a coil. This induces enough electricity to run the bicycle's lights. The faster the bicycle moves, the greater the induced voltage - and the brighter the lights.