Answer:
When the object is placed at the focus the image is formed at infinity.
Explanation:
When a ray passes through focus and incident on a concave mirror then it will travel parallel to principal axis after reflection.Hence the image is formed at infinity.
Answer
Pressure, P = 1 atm
air density, ρ = 1.3 kg/m³
a) height of the atmosphere when the density is constant
Pressure at sea level = 1 atm = 101300 Pa
we know
P = ρ g h


h = 7951.33 m
height of the atmosphere will be equal to 7951.33 m
b) when air density decreased linearly to zero.
at x = 0 air density = 0
at x= h ρ_l = ρ_sl
assuming density is zero at x - distance

now, Pressure at depth x


integrating both side


now,


h = 15902.67 m
height of the atmosphere is equal to 15902.67 m.
Answer:
Send a pic of it so i can mark it.
Explanation:
GIVEN:
60 beats per minute
21 beats per minute
find x= how fast would an astronaut be flying away
1 x
----- * ------ = (60x = 21) -------> 60x = 21 ------------> x= 0.35
60 21 ------- -----
60 60
The answer is 0.35 seconds which refers to how fast would an astronaut be flying away from the earth if he has a heart rate of 21 beats/min.
Answer:
30.5 x 10³ min.
Explanation:
Atomic weight of aluminium = 27
For the reaction
Al⁺³ + 3e = Al
3 mole of electron is required by 1 mole of aluminium
3 x 96500 C of charge is required for 27 gram of aluminium
60.2 g aluminium will require

645.47 x 10³ C
So charge required = 645.47 x 10³ C
Now Charge = Current x time
Current ( given ) = 0.352A
Time = charge / current = 645.47 x 10³ / .352
=1833 x 10³ s
30.5 x 10³ minutes