Answer:
i) 21 cm
ii) At infinity behind the lens.
iii) A virtual, upright, enlarged image behind the object
Explanation:
First identify,
object distance (u) = 42 cm (distance between object and lens, 50 cm - 8 cm)
image distance (v) = 42 cm (distance between image and lens, 92 cm - 50 cm)
The lens formula,
Then applying the new Cartesian sign convention to it,
Where f is (-), u is (+) and v is (-) in all 3 cases. (If not values with signs have to considered, this method that need will not arise)
Substituting values you get,
i)
f = 21 cm
ii) u =21 cm, f = 21 cm v = ?
Substituting in same equation
v ⇒ ∞ and image will form behind the lens
iii) Now the object will be within the focal length of the lens. So like in the attachment, a virtual, upright, enlarged image behind the object.
I think this is the best way to explain it
light from the sun takes 8 minutes and 20 seconds to travel to Earth. So it would be the same if the Earth's light to travel to the sun. The sun is described to be a star.
Answer:All are correct
Explanation:
All the given option is correct as the relation between load w,shear force V, and bending moment M is
and
Also the Shear at a section is equal to previous section plus the total load between two required section .
Same is true for Bending Moment
Answer:
average acceleration = 2.74 x 10⁻³ rad/s²
Explanation:
given,
CD playing time = 76 minutes
initial angular speed of CD = 4.10 × 10² rev/min
=
= 42.9 rad/s
final angular speed of CD = 2.90 × 10² rev/min
=
= 30.37 rad/s
average acceleration =
=
average acceleration = 0.00274 rad/s²
average acceleration = 2.74 x 10⁻³ rad/s²
Answer:
A. elements of the same kind with different numbers of neutrons
Explanation:
As we know that an atom is represented by
here we know that
z = atomic number
A = atomic number + number of neutrons
now if the number of neutrons in an atom is different but having same number atomic number then the combination of such group of atoms is known as isotopes.
So here we have
so above is the example of isotopes