Answer:
The focal length of the appropriate corrective lens is 35.71 cm.
The power of the appropriate corrective lens is 0.028 D.
Explanation:
The expression for the lens formula is as follows;
Here, f is the focal length, u is the object distance and v is the image distance.
It is given in the problem that the given lens is corrective lens. Then, it will form an upright and virtual image at the near point of person's eye. The near point of a person's eye is 71.4 cm. To see objects clearly at a distance of 24.0 cm, the corrective lens is used.
Put v= -71.4 cm and u= 24.0 cm in the above expression.
f= 35.71 cm
Therefore, the focal length of the corrective lens is 35.71 cm.
The expression for the power of the lens is as follows;
Here, p is the power of the lens.
Put f= 35.71 cm.
p=0.028 D
Therefore, the power of the corrective lens is 0.028 D.
Biceps curls & pushups , benchpress
Answer:
ultra sounds have frequency higher than the upper audible limit of human hearing, for healthy, young adults.
Explanation:
Answer:
angle minimum θ = 41.3º
Explanation:
For this exercise let's use Newton's second law in the condition of static equilibrium
N - W = 0
N = W
The rotational equilibrium condition, where we place the axis of rotation on the wall
We assume that counterclockwise rotations are positive
fr (l sin θ) - N (l cos θ) + W (l/2 cos θ) = 0
the friction force formula is
fr = μ N
fr = μ W
we substitute
μ m g l sin θ - m g l cos θ + mg l /2 cos θ = 0
μ sin θ - cos θ + ½ cos θ= 0
μ sin θ - ½ cos θ = 0
sin θ / cos θ = 1/2 μ
tan θ = 1/2 μ
θ = tan⁻¹ (1 / 2μ)
θ = tan⁻¹ (1 (2 0.57))
θ = 41.3º
Both
in the domestic and international guidelines tell that when two power-driven
vessels are crossing so as to contain risk of collision, the vessel which has
the other on her starboard side (the give-way vessel) must keep out of the way.
If
you are the give-way vessel, it is your responsibility to avoid a collision. Normally,
this means you must change speed or direction to cross behind the other vessel
which is the stand-on vessel.
At
evening, when you perceive a red light crossing right-to-left in front of you,
you need to change your course. But if you perceive a green light crossing from
left-to-right, you are the stand-on vessel, and should maintain course and
speed.
The leading situations of collision risk are meeting head-on, overtaking, and crossing. When one of two vessels is to keep out of the way (give-way vessel), the other, the stand-on vessel, must uphold course and speed.
