Answer:
(a): I = 4.6875 A
(b): P = 562.5 W
(c): P mech = 492.1875 W
Explanation:
Data Given:
V= 120 V
E= 105 V
R= 3.2 Ω
To find:
(a): I = ?
As we know that in a DC series motor the equation to be used will be:
V = Ε + (I) (R)
120 V = 105 V + ( I ) (3.2 Ω),
I= 15/3.2
I= 4.6875 A ans
Now moving towards Power delivered i.e.
(b): P del :
P del = V X I = (120 V) (4.6875 A) = 562.5 W. ans
c) P mech = ?
The mechanical power output is the electrical power input minus the rate of dissipation of energy in the motor’s resistance (assuming that there are no other power losses):
The power P dissipated in the resistance r is
P dsptd = I²r = (4.6875 A)² X(3.2 Ω) = 70.3125 W
P mech = P del - P dsptd
P mech = 562.5 W — 70.3125 W = 492.1875 W Ans
Hope it is clear
Answer:
c. streak
Explanation:
Pyrite is a mineral that looks like gold but actually is iron disulfide.
Pyrite and gold have comparable luster.
Pyrite and gold have different tones of yellow. This can be determined by their streak. Streak is the powdered form of a mineral. A streak of mineral can be found just by rubbing the mineral on a rough surface and comparing the colors.
Pyrite is diamagnetic which is not a strong form of magnetism. Gold is also diamagnetic
You've definitely got the right idea and your procedure is correct.
But I see one mistake for sure, plus a few other things that
I'm not sure of.
The mistake for sure: If the ending water is 12 ml,
then the beginning water is 9 ml, not 11 ml.
Things I'm not sure of:
-- I'm not sure that I'm remembering correctly at the moment,
but I have a sneaking hunch that you're supposed to read the
level at the BOTTOM of the meniscus, not the top.
It won't matter, because the DIFFERENCE will be the same
either way. But if the teacher wants you to read from the bottom,
then your numbers may be marked wrong.
-- The question at the bottom asks for the "volume of cherry",
but I seem to see TWO cherries in the water. Does than mean
they expect you to take only half of the displacement ?
-- They ask for "volume of cherry" twice.
Maybe that means they want you to end up with the volume in cm³
instead of ml. (The number is the same.)
Answer:
Work is defined as the amount of movement done by a force, and it can be calculated as:
W = f*d
where W is the work, f is the force and d is the distance.
So when the coach hits the ball, he is appliying some force in the ball (via the bat) that impulses the ball briefly (we can considerate that the force is only applied in a differential of time dt)
But we have a force applied and a displacement of the ball, so yes, the bat does work on the ball.