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:
In order of increasing frequency: Radio, Microwaves, Infrared, Visible light, Ultra-violet, X-rays, Gamma rays. To remember this try:
Rabbits
Mates
In
Very
Unusual
e(X)pensive
Gardens
Answer:
The radius r of the metal sphere.
Explanation:
From Gauss's law we know that for a spherical charge distribution with charge 
, the electrical field at distance 
from the center of the sphere is given by
What is important to notice here is that the radius of the sphere does not matter because any test charge sitting at distance feels the force as if all the charge were sitting at the center of the sphere.
This situation is analogous to the gravitational field. When calculating gravitational force due to a body like the sun or the earth, we take not of only the mass of the sun and the distance from it's center; the sun's radius does not matter because we assume all of its mass to be concentrated at the center.
Answer:
6.875 m/s
Explanation:
The force is variable which is given by
F(x) = 18 - 0.53 x
mass of the box, m = 8.9 kg
initially it is at rest at x = 0
Let the velocity is v after travelling a distance of 15 m.
According to the work energy theorem, the work done by all the forces is equal to the change in kinetic energy of the body.
Work done = change in kinetic energy
18 x 15 - 0.265 x 15 x 15 = 4.45 x v²
270 - 59.625 = 4.45 v²
v² = 47.275
v = 6.875 m/s
Thus, the final velocity of the box is 6.875 m/s.
Answer:
Galileo Galilei
Explanation:
although Galileo was not the scientist who invented the telescope, he was the first to use it to observe celestial objects. he used the telescope in 1609. his discovery included more accurate information about the moon, the sun and some of the planets.
