20.00
I hope this helps :)
The ball drops 72 inches (6 feet).
The ball bounces back 49 inches (4 feet, 1 inch).
49/72 = 68.05%
So yes, the ball (barely!) passes inspection.
Answer:
Step-by-step explanation:
Two answers are possible.
One is with the repetition of digits.
The other is without repetition of digits.
ANSWER 1: With Repetition
Numbers: 1,2,4,5,7,8
There are 4 digits __ __ __ __
1st digit can be filled by any of the 6 numbers.
Similarly 2nd, 3rd and 4th digits.
Hence each digit will have 6 possibilities.
Therefore no.of 4 digit numbers that can be formed are 6 x 6 x 6 x 6 = 1296
ANSWER 2: Without Repetition
4 digits __ __ __ __
Now the first digit can be filled by any of the six numbers. Therefore there are 6 possibilities
The second digit will have only 5 possibilities as one of the numbers gets used up by the 1st digit.
Similarly the 3rd and 4th digits will have 4 and 3 possibilities respectively.
Therefore no.of 4 digit numbers that can be formed are 6 x 5 x 4 x 3 = 360
R = ?
L = 3.1 m;
r = 1.7 mm/ 2 = 0.85 mm = 0.85 * 10^(-3) m
Resistivity of copper ( rho ) = 1.68 * 10 ^(-8) [Ohm m ]
A = 3.15 * ( 0.85 * 10^(-3))^2 = 2.26865 * 10 ^(-6)
R = ( Rho ) * L / A = 1.68 * 10^(-8) * 3.1 m / 2.26865 * 10^(-6) =
= (1.7 * 3 .1 / 2.26865 )* 10^(-2) = 0.02323 Ohms ( the resistance )
