Answer:
W = 9.6 N
Explanation:
Given that,
Area on 1 foot, A = 0.6 m²
Pressure, P = 16 Pa
The pressure is given by force acting per unit area. So,

So, the required weight is 9.6 N.
Answer:
quark
Explanation:
neutrón= 1.675 x 10-27 kg
proton=1,673 x 10-27 kg
electron=9,11 x 10-31 kg
quark=7,13 - 14,26 · 10−30 kg
Answer:
<em>The statement is true</em>
Explanation:
<u>Energy Conversion
</u>
When an object starts to fall in free air, it speeds up as it falls. The force of gravity acting on the object causes energy to be transferred from its gravitational potential energy to its kinetic energy. We can safely say the height converts to speed and vice-versa. If no external forces act on the system, we can easily calculate heights and speeds by knowing the total mechanical energy (gravitational potential plus kinetic) is conserved.
Answer:

How much gravitational potential energy does the block have
when it gets to the top of the ramp ?
(weight) x (height) = (15 N) x (0.2 m) = 3 Joules .
If there were no friction, you would only need to do 3 Joules of work
to lift the block from the bottom to the top.
But the question says you actually have to do 4 Joules of work
to get the job done.
Friction stole one of your Joules along the way.
Choice-4 is not the correct one.
Choice-1 is the correct one.
===========================
Notice that the mass of the block is NOT 15 kg , and you
don't have to worry about gravity to answer this question.
The formula for potential energy is (m)·(g)·(h) .
But (m·g) is just the WEIGHT, and the formula
is actually (weight)·(height).
The question GIVES us the weight of the block . . . 15 N .
So the potential energy at the top is just (15N)·(0.2m) = 3 Joules.