Answer:
Explanation:
Power P = V² / R
a ) The resistance is changed to 2.90R
Power will become 1 / 2.9 times .
b )The voltage of the battery is now 2.90V, but the resistance is R
P = (2.9V)² / R
= 8.41 x V² / R
So power becomes 8.41 times
c )The resistance is 2.90R and voltage is 2.90V
Power P = (2.9V)² / 2.9 R
= 2.9 V²/R
So power becomes 2.9 times
d ) The resistance is 2.90R and the voltage is V/2.90
Power P = ( V/2.90)² x 1 / 2.90R
1 / ( 2.9 )³ x V² / R
= 1 / 24.389 x V² / R
So power becomes 1 / 24.389 times .
Given: The number = 0.0069 that has to be expressed in scientific notation
Concept: When we express any number in scientific notation then we shall consider two points.
(i) If we shift the decimal point from left to right after first (non-zero) digit then we count the number of shifted place of decimal and write them in terms of the negative power of 10. For example, 0.004789 = 4.789 ×10⁻³
(ii) If we shift the decimal point from right to left after first (non-zero) digit from the left end then we count the number of shifted place and write then in terms of the positive power of 10. For example, 4789.24 = 4.78924 ×10⁺³ = 4.78924 ×10³ Now, we shall convert the given number 0.0069 in scientific notation
0.0069 = 6.9 ×10⁻³ because we have shifted the decimal from left to right for three places that is after digit 6.
Hence, the last option 6.9 ×10⁻³ will be the correct option.
AS
work done =W = F.d = F d cosФ (Ф is angle between force F and displacement d) If a body/object is moving on a smooth surface (friction-less surface ) .There is no force acting on that body. F=0 so W=FdcosФ= (0)dcosФ ⇒ W=0
Now if a body is facing some amount of force but under the action of force there is no displacement covered. d=0 so W =FdcosФ= F(0)cosФ ⇒W=0
example: A person is applying a force on rigid wall but wall remains at rest there is no displacement occurs in wall.
The third term upon which work done dependent is angle between force and displacement i.e Ф. If Ф=90° then W= FdcosФ= Fdcos90⇒ W=0 ( as cos 90°=0)
Answer:
Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance. A fast-moving object has a high speed and covers a relatively large distance in a short amount of time.
Explanation:
The formula for speed is speed = distance ÷ time. To work out what the units are for speed, you need to know the units for distance and time.
The circuit was installed in UF cable which requires a minimum burial depth of 6 inches for this circuit.
<h3>
UF cable</h3>
UF cable is used as an underground feeder cable to distribute power from an existing building to outdoor equipment. UF cable can also be used as direct burial cable.
For the 24-volt branch circuit installed, the minimum burial depth will be 6 inches.
Thus, the circuit was installed in UF cable which requires a minimum burial depth of 6 inches for this circuit.
Learn more about UF cable here: brainly.com/question/8591560
