Driving a motor........
chemical energy is converted into kinetic energy.
Falling off of cliff
.........gravitational potential energy is converted into kinetic energy.
Hydroelectric energy generation
.......gravitational potential energy is converted into kinetic energy (i.e. driving a generator), which is then converted into electrical energy.
Nuclear power generation
.........mass is converted into energy, which then drives a steam turbine, which is then converted into electrical energy.
Answer:
|F| = 393750 N
Explanation:
Given that,
Total mass of the train, m = 750000 kg
Initial speed, u = 84 m/s
Final speed, v = 42 m/s
Time, t = 80 s
We need to find the net force acting on the train. The formula for force is given by :
F = ma

So, the magnitude of net force is 393750 N.
m = mass = 5 kg
= initial velocity = 100 m/s
= final velocity = ?
I = impulse = 30 Ns
Using the impulse-change in momentum equation
I = m(
-
)
30 = 5 (
- 100)
= 106 m/s
here as it is given that x component of the vector is positive while y component of the vector is negative so we can say the vector must inclined in Fourth quadrant.
So angle must be more than 270 degree and less than 360 degree
Now in order to find the value we can say that




so it is inclined at above angle with X axis in fourth quadrant
Now if angle is to be measured counterclockwise then its magnitude will be

so the correct answer will be 305 degree
<span>K.E = 0.5 * m * v^2 ( m = mass(Kg), V = Velocity(m/s)
= 0.5 * 8 * 5^2
= 4 * 25
= 100 J </span>