Answer:
I'm pretty sure it's the third one where velocity goes from positive to negative
Explanation:
the positive velocity is before the object hits the ground and the negative is after
Complete question is;
A 50.-ohm resistor, an unknown resistor R, a 120-volt source, and an ammeter are
connected in a complete circuit. The ammeter reads 0.50 ampere.
A) Calculate the equivalent resistance of the circuit shown.
B) Determine the resistance of resistor R shown in the diagram.
Answer:
A) R_eq = 240 Ω
B) R = 190 Ω
Explanation:
A) To get the equivalent resistance, we will use the formula;
R = V/I
Where;
V is Voltage
I is current
R is equivalent resistance
From the question, V = 120 V and I = 0.5A
Thus;
R_eq = 120/0.5
R_eq = 240 Ω
B) From the image, we see that the resistors are connected in series.
Formula for resistors in series is;
R = R1 + R2 +..... Rn
Thus;
240 = 50 + R
R = 240 - 50
R = 190 Ω
Answer:
- Direct current is a current in which electrons flow in one direction only
- Alternating current is a current in which the direction of the electron flow reverses periodically - so, half a cycle forward, half a cycle backward
There are several advantages of using alternating currents for the transmission of electricity across a country, over large distances. The main advantages are:
- The voltage of alternating currents can be easily increased/decreased by using transformers. For instance, a transformer is used at the beginning of the transmission line to increase the voltage (electricity is transmitted at high voltage in order to reduce dissipated power), and then another transformer is used before the electricity enters the houses, in order to decrease the voltage. Transformers only work with alternating currents.
- It is easy to interrupt the flow of an alternating current, because its value naturally becomes zero every half a cycle, so this is useful in case the current must be interrupted.
To determine the mass of gold dissolved in oceans, we must first know the volume of the ocean in liters. To determine its volume, we multiply the area and the depth taking note of the consistency of units. The volume would be 1.38 x 10^18 cubic meters or 1.38x10^21 liters. Then,multiplying this to the concentration, the answer would be 8 x 10^12 grams or 8 billion kg.
Explanation:
PE= mgh
6 J= (3m) (9.81 m/s2) (mass)
mass=( 6)/(3×9.81)
mass= 0.20 Kg