What type of change occurs when water changes from solid to a liquid a phase change a physical change and irreversible change both A and the
-- In order to achieve constant verlocity, the net force on the mass must be zero. So if there ARE any forces acting on it, they must be balanced.
-- There is already a force on the mass that can't be eliminated . . . the force of gravity.
-- That force due to gravity is (mass x gravity) = (25 kg)(9.8 m/s²) = <em><u>245N</u></em> in the <u><em>downward</em></u> direction.
-- In order to 'balance' the forces and make them add up to zero, we have to provide another force of <em>245N</em>, all in the <em>upward</em> direction.
-- Then the forces on the object will be balanced, the NET force on it will be zero, and whichever way you start it moving, it will continue to move at a cornstant verlocity.
Answer:
<em>from the equation 1 below, the ratio of the resistivity of wire b to its resistance is twice the ratio of the resistivity if wire A to its resistance.</em>
Explanation:
<em>R=(ρL)/A</em>
<em>A =(ρL)/R</em>
<em>Where A is cross sectional area,</em>
<em>ρ is the resistivity</em>
<em>L is length of wire</em>
<em>R is resistance of wire.</em>
from the question the two wires have same cross sectional area.
Aa =Ab ; hence
(ρaLa)/Ra = (ρbLb)/Rb
La =2Lb
(ρa*2Lb)/Ra = (ρbLb)/Rb
(2ρa)/Ra = (ρb)/Rb
ρb/Rb = 2* ρa/Ra ................... equ 1
