B is the right answer. Multiply numbers you get the answer
The buoyant force exerted by a liquid is equal to the weight of the fluid <span>displaced.</span>
-- The speed of light in air is very close to 3 x 10⁸ m/s.
Whatever the actual number is, it's equivalent to roughly
7 times around the Earth in 1 second. So for this kind of
problem, you can assume that we see things at the same time
that they happen; don't bother worrying about how long it takes
for the light to reach you.
-- For sound, it's a different story. Sound in air only travels at
about 340 m/s. It takes sound almost 5 seconds to go 1 mile.
-- Now, the lightning and thunder happen at the same time.
The light travels to you at the speed of light, so you see the
lightning pretty much when it happens. But the sound of the
thunder comes poking along at 340 m/s, and arrives AFTER
the sight of the lightning.
The length of time between the sight and the sound is about
99.9999% the result of the time it takes the sound to reach you.
If the thunder arrived at you 3 seconds after the light did, then
the sound traveled
(340 m/s) x (3 s) = 1,020 meters .
(about 0.63 of a mile)
(If you're worried about ignoring the time it takes
for the light to reach you ...
It takes light 0.0000034 second to cover the same 1,020 meters,
so including it in the calculation would not change the answer.)
<h3><u>
For the aceleration:</u></h3>
First, let's find the resultant, and <u>applicate 2nd law of Newton</u> using the resultant, so:
R = ma
F - Ff = ma
Data:
F = Force = 1150 N
Ff = Friction force = 490 N
m = Mass = 150 kg
a = Aceleraction = ?
Replacing according our data:
1150 N - 490 N = 150 kg * a
660 N = 150 kg * a
660 N / 150 kg = a
a = 4,4 m/s² ← Aceleration of the object
<h3><u>For the normal force:</u></h3>
The normal force IS NOT the resultant force, the normal force's the force between the ground and the object, in another words, is the weight of the object, and for the weight:
w = mg
w = 150 kg * 10 m/s²
w = 1500 N ← Normal force between object and ground.
Answer:
=8.0 Watts
Explanation:
Power is a ratio of work done over time. The power in an electric circuit is calculated using the following formula:
P=I²R
P is power, I is current, R is resistance
Therefore, Power= 4²ₓ 0.5Ω
=8.0 Watts
