Momentum is one of those things that are 'conserved' (like energy). That means the total amount of momentum in an isolated system is the same after some event as it was before the event.
Before the ear-splitting explosion, while the firecracker and the billiard balls were just sitting there on the frictionless table, the momentum of the system was zero, because nothing was moving. Right there, that tells us that the total momentum of all the balls and the fragments of the firecracker ... if you add up all the momentum vectors AFTER the explosion ... the sum is still zero. (D)
Answer:
best explanation of this is sentence B
Explanation:
The radiation emission of the bodies is given by the expression
P = σ A e T⁴
Where P is the power emitted in watts, σ is the Stefan-Boltzmann constant, A is the surface area of the body, e is the emissivity for black body e = 1 and T is the absolute body temperature in degrees Kelvin.
When the values are substituted the power is quite high 2.5 KW, but the medium surrounding the box also emits radiation
T box ≈ T room
P box ≈ P room
As the two powers are similar and the box can absorbed, since it has the ability to emit and absorb radiation, as the medium is also close of the temperature of the box, the amount emitted is very similar to that absorbed, so the net change in energy is very small.
In the case that the box is much hotter or colder than the surrounding medium if there is a significant net transfer.
Consequently, the best explanation of this is sentence B
Answer:
3 m
Explanation:
At last, Same line; so, 6-3 = 3
Answer:
For the bird moving in a straight line, the kinetic energy is one-half the product of the mass and the square of the speed: Ek=12mu2.
