if rebecca stands in front of david at a distance of do and david perceives the position of rebecca at di, di will be +84 cm
<h3>What is focal length ?</h3>
How strongly light converges or diverges depends on an optical system's focal length, which is the inverse of optical power. A system with a positive focus length is said to converge light, whereas one with a negative focal length is said to diverge light.
focal length = +60 cm
magnification m = -0.40
focal length being positive an magnification negative.
given lens is a convex lens.
for a lens
m = di/do and 1/f = (1/di) - (1/do)di
= -0.4do1/f = (1/-0.4do) - 1/do do
= -210 cmdi = -0.4 * -210
di = +84 cm
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Answer: 1231.2 km/h
Explanation: 342 x 3.6 ( because 1 m/s equal 3.6 km/h)
Answer:
Since the resistors are in series, all of them carry the same current I.
if the potential drop across the 12 Ω is 4 V
I = 4 / 12 = 1/3 = .333 amp
a) 25 Ω * .333 amp = 8.33 V
b) 62 V * .333 amp = 20.7 V
Answer:
Explanation:
Let v be the terminal velocity of the bar .
emf induced in the bar of length L
= B L v where B is the value of magnetic field.
current i in the circuit containing resistance R
i = induced emf / R
BLv / R
Magnetic force in upward direction in the bar
F = BiL
= BL x BLv / R
B²L²v / R
For attainment of uniform velocity
magnetic force = weight
B²L²v / R = mg
so current
i = BLv / R