Let original length be L. The new length is therefore 4L.
Let original cross sectional surface area of the wire be equal to πr^2.
This means original volume was L x πr^2 = Lπr^2
The volume is the same but the length is different so 4L x new surface area must be equal to Lπr^2. Let new surface area be equal to Y.
4L x Y = Lπr^2
=> Y = (πr^2 )/ 4
Using the resistivity formula,
R = pL/A. p which is resistivity is a constant so it stays the same
But this time, instead of L we have 4L and instead of πr^2 we have (πr^2)/4.
so the new resistance
= (4Lp)/ {(πr^2)/4}
= 16 (pL)/(πr^2)
= 16 (pL)/A. because πr^2 is A
since pL/A is equal to R from the formula, this is equal to
16 R.
R was 10 ohms
therefore new resistance is 16 x 10 = 160 ohms
You just told us that Weight = (mass) x (gravity),
and that mass=10kg and gravity = 9.8 m/s².
All we need to do is write those numbers in place of the letters.
Weight = (10 kg) x (9.8 m/s²) = <em>98 newtons</em>.
Answer:
The work function of the metal is 2.226 eV.
Explanation:
Given;
wavelength of the violet light, λ = 427 nm = 427 x 10⁻⁹ m
maximum kinetic energy, K.E = 0.684 eV
The energy of the incident light is calculated as;
Apply Einstein's photoelectric equation;
E = Ф + K.E
where;
Ф is the work function of the metal
Ф = E - K.E
Ф = 2.91 eV - 0.684 eV
Ф = 2.226 eV.
Therefore, the work function of the metal is 2.226 eV.
He would have potential, he hasn’t gone down the mountain yet so he remains potential
