Answer:
Explanation:
Let the specific heat of material be s
heat lost by material = m₁ s (T 1 - T ) , (T 1 - T ) is fall in temp , m₁ is mass of material
= .45 x s x (91 - 31.4 )
= 26.82 s
Heat gained by water
= m₂ cw (T2 - T )
1.3 x 4186 x ( 31.4 - 23 )
heat lost = heat gained
m₂ cw (T2 - T ) = m₁ s (T 1 - T )
1.3 x 4186 x ( 31.4 - 23 ) = .45 x s x (91 - 31.4 )
45711.12 = 26.82 s
s = 1704.36
electricity can't flow anymore if the wire isnt connected at the beginning
Answer:
A
Explanation:
The figure shows the electric field produced by a spherical charge distribution - this is a radial field, whose strength decreases as the inverse of the square of the distance from the centre of the charge:

More precisely, the strength of the field at a distance r from the centre of the sphere is

where k is the Coulomb's constant and Q is the charge on the sphere.
From the equation, we see that the field strength decreases as we move away from the sphere: therefore, the strength is maximum for the point closest to the sphere, which is point A.
This can also be seen from the density of field lines: in fact, the closer the field lines, the stronger the field. Point A is the point where the lines have highest density, therefore it is also the point where the field is strongest.
Ek = (m*V^2) / 2 where m is mass and V is speed, then we can take this equation and manipulate it a little to isolate the speed.
Ek = mv^2 / 2 — multiply both sides by 2
2Ek = mv^2 — divide both sides by m
2Ek / m = V^2 — switch sides
V^2 = 2Ek / m — plug in values
V^2 = 2*30J / 34kg
V^2 = 60J/34kg
V^2 = 1.76 m/s — sqrt of both sides
V = sqrt(1.76)
V = 1.32m/s (roughly)