Earth's surface warms up in the sunlight. At night, Earth's surface cools, releasing the heat back into the air. But some of the heat istrapped<span> by the greenhouse </span>gases<span> in the </span>atmosphere<span>. ... Greenhouse </span>effect<span> of Earth's </span>atmosphere<span> keeps some of the Sun's energy from escaping back into space at night.</span>
Answer:
7. (D) uniformly accelerated vertical motion
8. (A) zero
9. (A) zero
10. (C) parabolic
Answer:
The answer would be 450 m kg/s
Explanation/ Explanation / Example:
Provided an object traveled 500 meters in 3 minutes , to calculate the average velocity you should take the following steps: Change minutes into seconds (so that the final result would be in meters per second). 3 minutes = 3 * 60 = 180 seconds , Divide the distance by time: velocity = 500 / 180 = 2.77 m/s .
If this doesn't help let me know!
Back emf is 85.9 V.
<u>Explanation:</u>
Given-
Resistance, R = 3.75Ω
Current, I = 9.1 A
Supply Voltage, V = 120 V
Back emf = ?
Assumption - There is no effects of inductance.
A motor will have a back emf that opposes the supply voltage, as the motor speeds up the back emf increases and has the effect that the difference between the supply voltage and the back emf is what causes the current to flow through the armature resistance.
So if 9.1 A flows through the resistance of 3.75Ω then by Ohms law,
The voltage across the resistance would be
v = I x R
= 9.1 x 3.75
= 34.125 volts
We know,
supply voltage = back emf + voltage across the resistance
By plugging in the values,
120 V = back emf + 34.125 V
Back emf = 120 - 34.125
= 85.9 Volts
Therefore, back emf is 85.9 V.
The next step is -748 divide by -11 is 68 m (answer) the pic got cropped sorry