Answer:
0.71 kg
Explanation:
L = length of the steel wire = 3.0 m
d = diameter of steel wire = 0.32 mm = 0.32 x 10⁻³ m
Area of cross-section of the steel wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (0.32 x 10⁻³)²
A = 8.04 x 10⁻⁸ m²
ΔL = change in length of the wire = 1.3 mm = 1.3 x 10⁻³ m
Y = Young's modulus of steel = 20 x 10¹⁰ Nm⁻²
m = mass hanging
F = weight of the mass hanging
Young's modulus of steel is given as


F = 6.968 N
Weight of the hanging mass is given as
F = mg
6.968 = m (9.8)
m = 0.71 kg
The equation for this is very simple you add then you subtract then you get the answer then you divide then it all works out for you
53....................................
Explanation:
Answer:
(a) hypermetropia
(b) convex lens
(c) 133.33 cm
(d) - 21.05 cm
Explanation:
(a) As she is old age, so she is suffering from hypermetropia.
(b) It is the defect due to which a person is not able to see the nearby objects clearly, so it is cured by convex lens of suitable focal length.
(c) Power, P = + 0.75 D
Focal length is the reciprocal of power of lens.
f = 1/ P = 1/0.75
f = 133.33 cm
(d) v = -25 cm, f = 133.3 cm
use lens equation



u = - 21.05 cm