The reflection of Lin Yao at the back of the spoon must be an upright reflection of himself. The back of the spoon is the convex side. When Lin Yao will look at the inner side of the spoon, his reflection will be inverted. This is because the inner side of the spoon is the concave side.
Answer:
It is A upside down and smaller
Explanation:
i just grabbed a spoon and look at myself
it also depends on what side you are looking at if you look at the back side it a normal mirror but if you look at the front its upside down and smaller
To find the time, tr, it takes for the runner to cross the finish line, we can use one of the kinematic equations that relate displacement, initial velocity, acceleration, and time. Since the runner starts from rest, his initial velocity is zero, so we can use the equation:
Δx=v0t+21at2
where Δx is the displacement, v0 is the initial velocity, a is the acceleration, and t is the time. Plugging in the given values of Δx=d, v0=0, and a=ai, we get:
d=0+21ait2
Solving for t, we obtain:
t=ai2d
This is the expression for the time, tr, it takes for the runner to cross the finish line, in terms of d and ai.
Answer:
Incomplete questions check attachment for circuit diagram.
Explanation:
We are going to use superposition
So, we will first open circuit the current source and find the voltage Voc.
So, check attachment for open circuit diagram.
From the diagram
We notice that R3 is in series with R4, so its equivalent is given below
Req(3-4) = R3 + R4
R(34) = 20+40 = 60 kΩ
Notice that R2 is parallel to the equivalent of R3 and R4, then, the equivalent of all this three resistor is
Req(2-3-4) = R2•R(34)/(R2+R(34))
R(234) = (100×60)/(100+60)
R(234) = 37.5 kΩ
We notice that R1 and R(234) are in series, then, we can apply voltage divider rule to find voltage in R(234)
Therefore
V(234) = R(234) / [R1 + R(234)] × V
V(234) = 37.5/(25+37.5) × 100
V(234) = 37.5/62.5 × 100
V(234) = 60V.
Note, this is the voltage in resistor R2, R3 and R4.
Note that, R2 is parallel to R3 and R4. Parallel resistor have the same voltage, then voltage across R2 equals voltage across R34
V(34) = 60V.
Now, we also know that R3 and R4 are in series,
So we can know the voltage across R4 which is the Voc we are looking for.
Using voltage divider
V4 = Voc = R4/(R4 + R(34)) × V(34)
Voc = 40/(40+60) × 60
Voc = 24V
This is the open circuit Voltage
Now, finding the short circuit voltage when we short circuit the voltage source
Check attachment for circuit diagram.
From the circuit we notice that R1 and R2 are in parallel, so it's equivalent becomes
Req(1-2) = R1•R2/(R1+R2)
R(12) = 25×100/(25+100)
R(12) = 20 kΩ
We also notice that the equivalent of Resistor R1 and R2 is in series to R3. Then, the equivalent resistance of the three resistor is
Req(1-2-3) = R(12) + R(3)
R(123) = 20 + 20
R(123) = 40 kΩ
We notice that, the equivalent resistance of the resistor R1, R2, and R3 is in series to resistor R4.
So using current divider rule to find the current in resistor R4.
I(4) = R(123) / [R4+R(123)] × I
I(4) = 40/(40+40) × 8
I(4) = 4mA
Then, using ohms law, we can find the voltage across the resistor 4 and the voltage is the required Voc
V = IR
V4 = Voc = I4 × R4
Voc = 4×10^-3 × 40×10^3
Voc = 160V
Then, the sum of the short circuit voltage and the open circuit voltage will give the required Voc
Voc = Voc(open circuit) + Voc(short circuit)
Voc = 24 + 160
Voc = 184V.
Answer:
Explanation
The most famous and common example is Christmas tree lights. You can't tell easily by looking at them whether they are in series or parallel. But you sure know the difference when one of them burns out. When that happens, the whole string goes dead. No matter what you do (other than find out which bulb burned out) will not fix the problem.
Another example is anything that is temperature controlled. For example a furnace is controlled by a thermostat. When the room temperature reaches a certain point, the thermostat is constructed in a certain way so that it forms an open circuit and no current can flow through it. The furnace motor turns off and the furnace stops pumping hot air into a room.
Any motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path. This force is called the centripetal force which means "center seeking" force. The force has the magnitude
F = mv^2 / r
Where f is the centripetal force
M is the mass
V is the velocity
R is the radius
19 N = m ( 0.54 m/s)^2 / 0.36 m
Solving for m
M = 23.5 kg
Answer:
23
Explanation: