Answer:
D
Explanation:
According to newton's 2nd law rate of change of momentum is directly proportional to the force applied on the body. Since, net Force is zero this means momentum did not change or momentum of the body remained constant.
Hence, the system have constant value of momentum. Therefore, option D is correct.
The most important characteristics that are exhibited by metals are-
1- Metals are ductile
2-Most metals are conductive in nature.
3-Most metals are malleable.
4- Metals have strong inter molecular force of attraction between the.
5-Metals have luster.
6-Metals are sonorous.
Here we are given Tungsten filament.
Tungsten is a metal.So it must be conductive and as well as ductile in nature.
The electric filament that we are using in our electric bulb glows due to the heating effect of current.Hence the chosen substances for glowing electric bulb must have high melting point.
The melting point of tungsten is 1650 degree celsius which is very high.That's why it is used in electric bulb.
Hence the correct answer to the question is the third one i.e Tungsten is ductile,has a high melting point, and is electrically conductive.
Answer:
D) momentum of cannon + momentum of projectile= 0
Explanation:
The law of conservation of momentum states that the total momentum of an isolated system is constant.
In this case, the system cannon+projectile can be considered as isolated, because no external forces act on it (in fact, the surface is frictionless, so there is no friction acting on the cannon). Therefore, the total momentum of the two objects (cannon+projectile) must be equal before and after the firing:
But the initial momentum is zero, because at the beginning both the cannon and the projectile are at rest:
So the final momentum, which is sum of the momentum of the cannon and of the projectile, must also be zero:
Answer: the minimal force that you need to apply to move the bureau is F = 198.45N
Explanation:
If you want to move an object, you need to apply a force that is bigger than the force of the statical friction.
The force of statical friction can be written as.
Ff = k*N
where k is the coefficient of static friction, in this case, k = 0.45, and N is the normal force between the object and the surface.
In this case, the normal force is the weight of the bedroom bureau, this is:
N = m*g = 45kg*9.8m/s^2 = 441N
Then the force is:
Fr = 0.45*441N = 198.45N
This means that the minimal force that you need to apply to move the bureau is F = 198.45N
and after this point, the force of friction will work wit the kinetic coefficient of friction, that usually is smaller than the statical one.
Answer:
The answer is Mechanical Energy
