Answer:
A
Explanation:
If the object is moving at a constant speed, the object isn't accelerating as the velocity doesn't change.
Answer:
screw and pulley
Explanation:
because they didn't have any of the other tools in that time
Light waves are never 'aborted'.
They can be 'absorbed', and I think that's what you mean.
It's what happens when light hits something or goes into it,
and never comes out.
"Absorb" just means "soak up". When a light wave hits something and
gets soaked up in it, it's gone, and never comes out the other side.
The light wave certainly gets changed ... it no longer exists.
The object that absorbs it also gets changed. It soaks up the energy
in the light wave, and it has a little more internal energy (heat) than it
had before the light hit it.
Answer:
F = 614913.88 N
Explanation:
We are given;
Mass of pile driver; m = 1800 kg
Height of fall of pole driver; h = 4.6 m
Depth driven into beam; d = 13.6 cm = 0.136 m
Now, from energy equations and applying to this question, we can write that;
Workdone = Change in potential energy
Formula for workdone is; W = F × d
While the average potential energy here is; W = mg(h + d)
Thus;
Fd = mg(h + d)
Where F is the average force exerted by the beam on the pile driver while in bringing it to rest.
Making F the subject, we have;
F = mg(h + d)/d
F = 1800 × 9.81 × (4.6 + 0.136)/0.136
F = 614913.88 N
