Explanation:
It is based upon the fact that " The light travels faster then sound." As the speed of light is faster then the speed of sound, light travels 300,000 km per second and sound travels 1192 km per hour. That is why we observe the lightening first and hear the the sound of thunder later.
You can do this experiment by yourself. Once you see the lightening start counting the seconds until you hear the sound of thunder.Then divide the seconds by 5, you will find out how many miles away the lightening strike was.
Here we will say that there is no external torque on the system so we will have

here we know that

where we know that

Also we know that

initial angular speed will be

now from above equation



now we have

so final speed will be 2.41 rad/s
The equation you use is Ke = 1/2mv^2. when you plug in the numbers that are given you get Ke= 1/2(4)(2^2) which gives you a Kinetic Energy of 8
Answer:
El peso del cartel es 397,97 N
Explanation:
La tensión dada en cada segmento del cable = 2000 N
El desplazamiento vertical del cable = 50 cm = 0,5 m
La distancia entre los polos = 10 m
La posición del letrero en el cable = En el medio = 5
El ángulo de inclinación del cable a la vertical = tan⁻¹ (0.5 / 5) = 5.71 °
El peso del letrero = La suma del componente vertical de la tensión en cada lado del letrero
El peso del signo = 2000 × sin (5.71 grados) + 2000 × sin (5.71 grados) = 397.97 N
El peso del signo = 397,97 N.
Answer:
what do you need help with?
Explanation:
I would look up the periodic table of elements
hope this helps!