Because it’s cheaper and efficient
B) 20 cm
The height and distance will be the same. Only the image will be laterally inverted.
Given
Three 7 ohm resistor are in series.
The battery is V=10V
To find
The equivalent resistance
Explanation
When the resistance are in series then the resistance are added to find its equivalent.
Thus the equivalent resistance is:

Conclusion
The equivalent resistance is 21 ohm
Answer:
F = 2(50 N) - (50 N) = 50 N
Explanation:
The direction of F is the direction in which the two students are pushing.
Answer: D
Explanation: read the answers above and compare to your test