Answer:
Induced current, I = 18.88 A
Explanation:
It is given that,
Number of turns, N = 78
Radius of the circular coil, r = 34 cm = 0.34 m
Magnetic field changes from 2.4 T to 0.4 T in 2 s.
Resistance of the coil, R = 1.5 ohms
We need to find the magnitude of the induced current in the coil. The induced emf is given by :

Where
is the rate of change of magnetic flux,
And 



Using Ohm's law, 
Induced current, 

I = 18.88 A
So, the magnitude of the induced current in the coil is 18.88 A. Hence, this is the required solution.
In my opinion, calling exercise "work" wouldn't be a good way of describing it, I don't think people would exercise if its called work
In the above problem, we need to find mass of the second child, so that the Center of Mass remains at the origin( pivot).
CM= m1r1+m2r2/m1+m2
0= 20*-2+16*r2/20+16
r2= 40/16
r2= +2.5 m
Answer:
longitudinal engineering strain = 624.16
true strain is 6.44
Explanation:
given data
diameter d1 = 0.5 mm
diameter d2 = 25 mm
to find out
longitudinal engineering and true strains
solution
we know both the volume is same
so
volume 1 = volume 2
A×L(1) = A×L(2)
( π/4 × d1² )×L(1) = ( π/4 × d2² )×L(2)
( π/4 × 0.5² )×L(1) = ( π/4 × 25² )×L(2)
0.1963 ×L(1) = 122.71 ×L(2)
L(1) / L(2) = 122.71 / 0.1963 = 625.16
and we know longitudinal engineering strain is
longitudinal engineering strain = L(1) / L(2) - 1
longitudinal engineering strain = 625.16 - 1
longitudinal engineering strain = 624.16
and
true strain is
true strain = ln ( L(1) / L(2))
true strain = ln ( 625.16)
true strain is 6.44