<span>5.98 x 10^-2 ohms.
Resistance is defined as:
R = rl/A
where
R = resistance in ohms
r = resistivity (given as 1.59x10^-8)
l = length of wire.
A = Cross sectional area of wire.
So plugging into the formula, the known values, including the area of a circle being pi*r^2, gives:
R = 1.59x10^-8 * 3.00 / (pi * (5.04 x 10^-4)^2)
R = (4.77 x 10^-8) / (pi * 2.54016 x 10 ^-7)
R = (4.77 x 10^-8) / (7.98015 x 10^-7)
R = 5.98 x 10^-2 ohms
So that wire has a resistance of 5.98 x 10^-2 ohms.</span>
Well we can't see the picture that the teacher has, and we have to figure out what's in the picture from some clues in the answer choices. The picture seems to show an atom with 3 protons and 3 neutrons in the nucleus, and 3 electrons whizzing around the nucleus.
If that's what's in the picture, then Mike is correct (first choice), because the atomic number shows the number of protons in all atoms. There are 3 protons and the atomic number of lithium is 3.
Second choice . . . False, because electrons are not involved in the atomic mass.
Third and fourth choices . . . both false; sadly, Joan is woefully unclear on the concepts.
Answer:
Explanation:
graph would be a straight line from (0, 0) to (400, 8)
Plot points are
PE = mgh
50(0) = 0 J
50(2) = 100 J
50(4) = 200 J
50(6) = 300 J
50(8) = 400 J
The Answer to the question above is A. 2.7 x 102 joules.
The time per lap was calculated by measuring the time for seven laps and dividing the total time by seven.
total time 
It is given that the precision is of 0.1 s. it means it is correct upto 1 place beyond decimal.
So, the actual value could vary from 457.800 s to 457.899 s i.e. the time per lap could be 65.400 s to 65.414 s
It means measured time 65.414 s has maximum error of 0.021%. Hence, the measured value is quite precise.