Four regions of the electromagnetic spectrum that astronomers use when observing objects in the space are the following enumerated answers.
1. First is Ultraviolet
2. Next is Infrared
3. Then the radio
4. Lastly the Visible lights.
These are the answers to the problem.
Explanation:
formula for force is:
force=mass × acceleration
but in case of friction
force =coefficient of friction × Normal Reaction
F. = u × R
U = F/R
but when placed horizontally
R= M×G
M=mass=60kg
G=Gravity(10m/s or 9.8m/s)
F=140N
U=140/60×10
U=140/600
U=0.2333333333
approximately to 3 significant figures
U=0.233
if i am correct rate it 5 star
Answer:
42m/s
6.06s
Explanation:
To find the initial velocity and time in which the ball is fling over the ground you use the following formulas:

θ: angle = 45°
vo: initial velocity
g: gravitational constant = 9.8m/s^2
x_max: max distance = 180 m
t_max: max time
by replacing the values of the parameters and do vo the subject of the first formula you obtain:

with this value of vo you calculate the max time:

hence, the initial velocity of the ball is 42m/s and the time in which the ball is in the air is 6.06s
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TRANSLATION:
Para encontrar la velocidad inicial y el tiempo en el que la pelota está volando sobre el suelo, use las siguientes fórmulas:
θ: ángulo = 45 °
vo: velocidad inicial
g: constante gravitacional = 9.8m / s ^ 2
x_max: distancia máxima = 180 m
t_max: tiempo máximo
reemplazando los valores de los parámetros y haciendo el tema de la primera fórmula que obtiene:
con este valor de vo usted calcula el tiempo máximo:
por lo tanto, la velocidad inicial de la pelota es de 42 m / sy el tiempo en que la pelota está en el aire es de 6.06 s