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
<span>Which of the following substance are not formed by chemical bonds? </span>A MIXTURE
Answer:
a)
b) 
Explanation:
The net force on the car must produce the centripetal acceleration necessary to make this circle, which is 
. At the top of the circle, the normal force and the weight point downwards (like the centripetal force should), while at the bottom the normal force points upwards (like the centripetal force should) and the weight downwards, so we have (taking the upwards direction as positive):
Which means:
The limit for falling off would be 
, so the minimum speed would be:
The answer is full moon because that’s how it changes in life
<span>This reduction happens because potential energy transforms to "thermal energy" and "sound energy"
Hope this helps!</span>
