Answer:
The cross-sectional area of the larger piston is 800 cm².
Explanation:
Given;
mass of the automobile, m = 4000 kg
force applied on the small piston, F₁ = 500 N
area of the smaller piston, A₁ = 10 cm²
load lifted by the larger piston, F₂ = 4000 x 10 = 40,000 N
Pressure experienced by each piston is given as;

Where;
A₂ is the cross-sectional area of the larger piston

Therefore, the cross-sectional area of the larger piston is 800 cm².
From that list of choices, choice 'B' is the only example of a plane,
but it doesn't 'describe' it at all.
Answer:
(a) 
(b) 
Explanation:
(a) The surface current density of a conductor is the current flowing per unit length of the conductor.

Considering a wire, the current is uniformly distributed over the circumferenece of the wire.

The radius of the wire = a

The surface current density 
(b) The current density is inversely proportional
......(1)
k is the constant of proportionality

........(2)
substituting (1) into (2)





substitute 

Answer:
Precisely, water has to absorb 4,184 Joules of heat (1 calorie) for the temperature of one kilogram of water to increase 1°C. For comparison sake, it only takes 385 Joules of heat to raise 1 kilogram of copper 1°C.
Explanation:
Answer:
K = m g (A - A2)
Explanation:
In a block spring system the total energy is the sum of the potential energy plus the kinetic energy, for maximum elongation all the energy is potential
Em = U₀ = m g A
For when the system is at an ele
Elongation A2 less than A, energy has two parts
Em = K + U₂
K = Em –U₂
We substitute
K = m g A - m gA2
K = m g (A - A2)