Answer: Brittle
Explanation:
took the test and I chose Soft, Soft is the wrong answer don't choose it. The CORRECT ANSWER IS BRITTLE
Answer:
a) 70 N, b) b. Each initially applied a force bigger than static friction to get the box moving and accelerating, then when the desired final speed was achieved they reduced the force to make the net force zero.
Explanation:
a) A constant speed means that magnitude of friction force is equal to the magnitude of the external force. The friction force is directly proportional to the normal force, which is equal to the weight of the box. Therefore, the magnitude of the force is 70 N.
b) Alice used initially a greater force to accelerate the box up to needed speed and later reduced the external force to keep speed constant. The right choice is option b.
300/8 = 37.5
37.5 x 12 = 450
New temp. = 450 K
Hope this helps!
Answer:
4 times greater
Explanation:
<u>Step 1:</u> Calculate light-collecting area of a 20-meter telescope (A₁) by using area of a circle.
Area of circle = π*r² =
Where d is the diameter of the circle = 20-m
A₁ = 314.2 m²
<u>Step 2:</u> Calculate light-collecting area of a 10-meter Keck telescope (A₂)
Where d is the diameter of the circle = 10-m
A₂ = 78.55 m²
<u>Step 3</u>: divide A₁ by A₂
= 4
Therefor, the 20-meter telescope light-collecting area would be 4 times greater than that of the 10-meter Keck telescope.
The two points on a periodic wave in a medium are said to be in phase if they have the same amplitude and are moving in the same direction.
Option 4.
Explanation:
A periodic wave is termed for waves which flow in a repetition pattern in a given time scale. Periodic wave can also be termed as a transverse wave. So a transverse wave have various crests and troughs. The two successive crests and two successive troughs are said to be in phase with each other.
Thus, for a periodic wave in a medium, the in phase can be obtained in two points which have the same amplitude and are moving in the same direction.
As amplitude is a scalar quantity and so direction should be taken into consideration for making the points related to successive crests only in phase with themselves. Also this also relates the points related to successive troughs to be in phase with each other. But a crest and a trough will not be in phase with each other.
Thus, option 4, that is the two points on a periodic wave in a medium are said to be in phase if they have the same amplitude and are moving in the same direction.
