Compare and contrast lava and magma
1 answer:
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Answer:
(a) 89 m/s
(b) 11000 N
Explanation:
Note that answers are given to 2 significant figures which is what we have in the values in the question.
(a) Speed is given by the ratio of distance to time. In the question, the time given was the time it took the pulse to travel the length of the cable twice. Thus, the distance travelled is twice the length of the cable.
(b) The tension, , is given by
where is the speed,
is the tension and
is the mass per unit length.
Hence,
To determine , we need to know the mass of the cable. We use the density formula:
where is the mass and
is the volume.
If the length is denoted by , then
The density of steel = 8050 kg/m3
The cable is approximately a cylinder with diameter 1.5 cm and length or height of 620 m. Its volume is
Answer:
60 ft
Explanation:
The tree man and their shadow system forms two similar right angle triangles.
the figure is in the attachment.
let ∠BAC= θ
Therefore, in triangle ABC
tanθ = BC/AC= 35/75= 7/15
now in ΔAEF also
tanθ = EF/AE = 7/75-x= 7/15
solving we get x=60 ft
Now AC and FA are the shadows of the tree and the man respectively.
now FA =75-x=75-60= 15 ft
Therefore, the man must stand at a distance of 60 ft from the tree can you stand and still be completely in the shadow of the tree
