1. B
2.D
3.C
4.B
Hope this helped. Good luck!
Answer:
La aceleración total de la piedra es 2,85 m/s².
Explanation:
La aceleracion total de la piedra viene dado por la suma de la acelaración centrípeta y de aceleración tangencial, como:
La aceleración tangencial () es la aceleracion del cilindro igua a:
Entonces, la aceleración centrípeta es:
En donde:
v: es la velocidad tangencial de la piedra = 2,0 m/s
r: es el radio del cilindro = 1,5 m
Finalmente, el módulo de la aceleración total es:
Por lo tanto la aceleración total de la piedra es 2,85 m/s².
Espero que te sea de utilidad!
An object with a constant pushing or pulling force is exerted on it is greater than the frictional force, than A. The object will accelerate.
Answer:
The correct option is D
Explanation:
From the question we are told that
The speed of the first charge is
This is because it is at rest
The speed of the second charge is
Generally the force exerted by a magnetic field on a charge is mathematically represented as
Now looking at this above equation we can see that can only be maximum at and this only obtained when the direction of the charge (i.e its velocity ) is perpendicular to the direction of the magnetic field
so the correct option for this question is D
Answer:
Because the molecules are not packed together as much than the air, in a fixed volume of helium there are fewer particles than in the same fixed volume of air.
This means that the mass of the fixed volume of helium is smaller than the one of air, and then the density, defined as mass/volume, is also smaller.
This is why the balloon floats, because the air is denser, it tries to go down, pushing the ballon upside.
The case is similar for a piece of metal in water, as the metal is way denser than the water, the metal will sink, but for something not as dense, like a balloon with air, the balloon will remain in the surface of the water.