Autobus porusza się ze stałą prędkością 54 km/h Oblicz w jakim czasie przebędzie drogę 450 m
1 answer:
You might be interested in
Answer:
The speed decreases.
Explanation:
This can be explained using the conservation of linear momentum.
Since there is no friction, the initial moment of the train must be equal to its linear moment after it is filled with water.
the initial linear momentum is
where is the initial mass of the train, and
the initial speed of the train.
And linear momentum after the water filled the train car is
where is mass of the train after the rain, and
the speed of the train after the rain
<u>the equality must be fulfilled:</u>
We know that if water is added to the train, that is the mass after the water is added, is greater than
which is the mass of the train without the water.
Therefore, in order for the conservation of the linear momentum to be fulfilled:
the speed after the water is added ( ) must be smaller than the initial train speed (
) . So the speed of the car decreases.
Answer:
a
b
Explanation:
From the question we are told that
The mass of the rock is
The length of the small object from the rock is
The length of the small object from the branch
An image representing this lever set-up is shown on the first uploaded image
Here the small object acts as a fulcrum
The force exerted by the weight of the rock is mathematically evaluated as
substituting values
So at equilibrium the sum of the moment about the fulcrum is mathematically represented as
Here is very small so
and
Hence
=>
substituting values
The mechanical advantage is mathematically evaluated as
substituting values
