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:19.32 m/s
Explanation:
Given
initial speed of car(u)=4.92 m/s
acceleration(a)=
Speed of car after 4.5 s
using equation of motion
v=u+at
v=19.32 m/s
Displacement of the car after 4.5 s
s=54.54 m
Answer:
- 278.34 kg m/s^2
Explanation:
The rate of the change of momentum is the same as the force.
The force that an object feels when moviming in a circular motion is given by:
F = -mrω^2
Where ω is the angular speed and r is the radius of the circumference
Aditionally, the tangential velocity of the body is given as:
v = rω
The question tells us that
v = 25 m/s
r = 7m
mv = 78 kg m/s
Therefore:
m = (78 kg m/s) / (25 m/s) = 3.12 kg
ω = (25 m/s) / (7 m) = 3.57 (1/s)
Now, we can calculate the force or rate of change of momentum:
F = - (3.12 kg) (7 m)(3.57 (1/s))^2
F = - 278.34 kg m/s^2
Answer:
Here, force=20N and displacement=10m
Work=Force×Displacement=20N×10m=200Nm