Sm = small piston
la = large piston
P=F/A
P=15000/(20^2)π
F of sm = PA
= (75/2π)•((8^2)π)
= (75•64)/2
= 4800/2
= 2400N
We already know the pressure but giving it in an approximate decimal form, to two significant figures (since that's what your supplied precision is at):
a) 12 Pa
b) 2400 N
Since the horizontal velocity is what is doubled, that does not affect the fall of the ball, thus the fall is still 5 seconds long.
Energy is conserved. If the ball reaches a height of 5.50 m, it has gained a certain amount of gravitational potential energy. That energy had to come from somewhere. From this fact, you can deduce the speed of the ball at the end of the impact with the racket.
<h3>What is
gravitational potential energy?</h3>
Gravitational energy or gravitational potential energy is the potential energy a huge item has corresponding to one more monstrous article because of gravity. It is the potential energy related with the gravitational field, which is delivered (changed over into active energy) when the articles fall towards one another. Gravitational potential energy increments when two articles are brought further apart. It is the potential energy related with the gravitational field, which is delivered (changed over into dynamic energy) when the items fall towards one another. Gravitational potential energy increments when two items are brought further separated.
Learn more about gravitational potential energy, visit
brainly.com/question/13978841
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<span>here's a cheap trick
it would take the same time to accelerate from rest to top speed
as it would take to decelerate from top speed to zero
so
instead of
d = Vi t + 1/2 a t^2 where Vi is positive and a is negative
we'll use
Vi = 0 and a is positive
giving
85 = 0 + 1/2 (0.43) t^2 = 0.215 t^2
t^2 = 395.345
t = 19.88s or 20. s to 2 sig figs
or we ccould find Vi from
Vf*2 = Vi^2 + 2 a d
0 = Vi^2 + 2 (0.43) 85
Vi^2 = 71.4
Vi = 8.45m/s
then
85 = 8.45 t + 1/2 (-0.43) t^2
85 = 8.45 t - 0.215 t^2
0.215 t^2 - 8.45 + 85 = 0
t = 19.65s or 20. s to 2 s.f.(minor difference arises from rounding Vi)
or another cheap trick
when a is constant
Vavg = (Vf + Vi) /2 = 8.45/2 = 4.225
and
d = Vavg t
85 = 4.225 t
t = 20.12 or 20. s to 2 s.f. (minor differences from intermidiate roundings)
anyway you choose you get 20. s</span>
Answer:
c. absorbs all the energy that strikes it.
Explanation:
<em>An ideal black body is an object that absorbs every light energy (irrespective of the wavelength and direction) that strikes it without reflecting any in return. </em>
<em>Such objects or bodies usually appear perfectly black and will only emit radiation when heated to a very high temperature.</em>
