Answer:
310.5 J
Explanation:
The total work done by Martha is equal to the increase in gravitational potential energy of the package, which is equal to

where
(mg) = 45 N is the weight of the package
is the increase in height of the package
The package is carried up 3 flights of stairs, each one with a height of 2.3 m, so the total increase in heigth is

And so, the work done by Martha is

An object with non-zero mass (even negligible mass is non-zero) will never reach the speed of light. Due to relativistic effects, each "unit" of acceleration becomes less effective at increasing your velocity (relative to some other object, of course) as your relative velocity approaches the speed of light.
And even if there was a way, If you would accelerate to the 99,99% of the speed light in just 1 second, you would experience a G-force of aprox. 30,600,000 g's which is enough to kill you in a few seconds
Answer:
1995 and 2000 , 4 trillions
Explanation:
The situation (heat going through the ceiling) describes
conduction ... heat going from one place to another by
soaking through some material.
A). This is the one. Heat goes from from the marshmallow
to your hand by soaking through the wire. This is conduction too.
B). No. The heat in the room goes from the floor to the ceiling
because the warm air rises and carries it there. This is convection.
C). No. There's nothing for the heat to soak through between
the sun and the roof, and nothing that can move from the sun
to the roof and bring the heat with it. This is radiation.
D). No. Cold water sinks from the surface to the bottom because
warm water rose from the bottom to the surface, taking heat with it.
This is convection.