Answer:
option (E) is correct.
Explanation:
Work done is defined as the product of force and the distance in the direction of force.
force, f = 100 N
Coefficient of friction, = 0.25
distance = 15 m
So, net force F = f - friction force
F = 100 - 0.25 x m g
Work = (100 - 0.25 mg) x d cosθ
For minimum work, the angle should be maximum.
So, the value of θ is 76°.
thus, option (E) is correct.
Answer:
Explanation:
Near point = 56 cm .
near point of healthy person = 25 cm
person suffers from long sightedness
convex lens will be required .
object distance u = 25 cm
image distance v = 56 cm
both will be negative as both are in front of the lens.
lens formula
I/v - 1 / u = 1/f
- 1/56 +1/25 = 1/f
- .01785 + .04 = 1/f
1/f = .02215
f = 45.15 cm .
F - False.
The nucleus of an atom is positively charge.
Well, Harry, what you said is not necessarily true the way you said it.
But we know what you mean, and what you meant to say is true.
The Doppler effect is observed if there is relative radial motion
between an object and an observer <em><u>AND</u></em> if the object happens
to be putting out sound or light in the observer's direction.
