<span>This is actually all
because of centripetal acceleration and inertia. You see that when the bucket
spins, it actually tries to go straight, however the rope attached restricts
this and makes it go in a circle. This makes the water to be pinned against the
bottom of the bucket. </span>
To answer this question, it helps enormously if you know
the formula for momentum:
Momentum = (mass) x (speed) .
Looking at the formula, you can see that momentum is directly
proportional to speed. So if speed doubles, so does momentum.
If the car's momentum is 20,000 kg-m/s now, then after its speed
doubles, its momentum has also doubled, to 40,000 kg-m/s.
It is 800 N FN = 600N + 200 N = 800 N Answer to your question: The net force is all Newton's second law. It is the force that acts on a body or a particle. for example: It is the force we make when we push a car or something heavy that is in a straight line. .
The distance covered by car is equal to (assuming it is moving by uniform motion) the product between the car's speed and the time of the car ride, 4 h:

where

is the car's speed

is the duration of the car ride
Similarly, the distance covered by train is equal to the product between the train's speed and the duration of the train ride, 7 h:

The total distance covered is S=255 km, which is the sum of the distances covered by car and train:

which becomes

(1)
we also know that the train speed is 5 km/h greater than the car's speed:

(2)
If we put (2) into (1), we find

and if we solve it, we find


So, the car speed is 20 km/h and the train speed is 25 km/h.