Answer:
2f
Explanation:
The formula for the object - image relationship of thin lens is given as;
1/s + 1/s' = 1/f
Where;
s is object distance from lens
s' is the image distance from the lens
f is the focal length of the lens
Total distance of the object and image from the lens is given as;
d = s + s'
We earlier said that; 1/s + 1/s' = 1/f
Making s' the subject, we have;
s' = sf/(s - f)
Since d = s + s'
Thus;
d = s + (sf/(s - f))
Expanding this, we have;
d = s²/(s - f)
The derivative of this with respect to d gives;
d(d(s))/ds = (2s/(s - f)) - s²/(s - f)²
Equating to zero, we have;
(2s/(s - f)) - s²/(s - f)² = 0
(2s/(s - f)) = s²/(s - f)²
Thus;
2s = s²/(s - f)
s² = 2s(s - f)
s² = 2s² - 2sf
2s² - s² = 2sf
s² = 2sf
s = 2f
Answer:
D. 15 m/s downward
Explanation:
v = at + v₀
v = (-9.8 m/s²) (1.5 s) + (0 m/s)
v = -14.7 m/s
Rounded to two significant figures, the answer is D, 15 m/s downward.
Answer:
Explanation:
Velocity of plane relative to ground V_pg = ?
Given the velocity in vector form ,
velocity of plane relative to air V_pw = 120 cos30 i + 120sin30j
V_wg = 60 i
V_pg = V_pw +V_wg
= 120 cos30 i + 120sin30j + 60i
= 164 i + 60 j
magnitude
=251 km / h
=
Answer:
angular velocity(ω) is the rate change of angular displacement.
ω=θ/t and it SI unit is rad/s
Explanation:
this is very similar with the definition of linear velocity (rate of change of displacement). it specifies the angular speed of an object and the axis about which the object is rotating.
