Waves have the
characteristic that they can of transmit energy. This characteristic depend
only on the medium and its properties. Electro-mechanical waves do not need
medium to transfer its energy, is capable of transmitting it through empty
space (vacuum).
<span>Mechanical
waves require a medium in order to transport their energy. Sound waves are an
example of mechanical way. They can not
travel through vacuum. </span>
This isn't a physics question really, but you should slow down unless you don't believe you can stop in time or don't believe it is safe to stop quickly (say you see someone driving very close behind you and you don't think they're paying attention). In general, if you think that by staying at your current speed your back tires will cross the ending lines of the intersection by the time the light turns red, it is safe to go through the yellow light. However, this is a thing you'll develop a feel for as you're driving, when in doubt, just slow down, just watch slamming on your breaks if there is someone behind you, sometimes people will see the yellow light when they're behind you and they'll speed up behind you so they'll "make it" before the light turns yellow. While this isn't illegal, since they're not technically running the red light, you should never speed up going up to a yellow light, if you need to speed up to make it before it turns red, you shouldn't make the light, just stop, this is especially bad if someone is directly in front of you and is likely to stop at the yellow light while the person behind them speeds up. This causes a lot of accidents.
Protons, electrons, and neutrons. The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge).
When you squish the spring, you put some energy into it, and after the cord
burns and they go boing in opposite directions, that energy that you stored
in the spring is what gives the blocks their kinetic energy.
But linear momentum still has to be conserved. It was zero while they were
tied together and nothing was moving, so it has to be zero after they both
take off.
Momentum = (mass) x (velocity)
After the launch, the 5.5-kg moves to the right at 6.8 m/s,
so its momentum is
(5.5 x 6.8) = 37.4 kg-m/s to the right.
In order for the total momentum to be zero, the other block has to
carry the same amount of momentum in the opposite direction.
M x V = (6 x speed) = 37.4 kg-m/s to the left.
Divide each side by 6 : Speed = 37.4 / 6 =<em> 6.2333... m/s left</em>
(That number is (6 and 7/30) m/s .)
