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:
v = rw
Explanation:
When an object is rolling continuously without slipping, then every angle it rotates through, is equal to a distance the perimeter has rotated.
If the object completes 10 revolutions and takes a particular time, let's say t to complete it. The angular distance would then be 20 π rad, while its angular velocity will be 20 π/t
The circumference will somehow translate to the distance it covers, which is 20πr, this means that the speed is 20πr/t
So, like the question asked, the linear speed compared to angular speed is
v : w
20πr/t : 20πt, which can be simplified to
r : 1
In essence, v = rw
Answer:
Student A is correct
Explanation:
Colored objects look the way they do because of reflected light. When sunlight is shined on a green leaf, the violet, red and orange wavelengths are absorbed. The reflected wavelengths appear green. In each case we are seeing the complementary colors to the ones absorbed.
