Answer:
Mary's average speed is 0.42 meters/second.
Explanation:
Mary's total travel was 250 meters and the elapsed time was 10 minutes, equivalent to 600 seconds.
d = displacement = 80 meters + 125 meters + 45 meters = 250 meters
t = time = 10 minutes . 60 seconds/minute = 600 seconds
We can obtain now the average speed:
s = average speed = displacement / time = 250 meters / 600 seconds ≅ 0.4167 ≅ 0.42
Um tubo de raios-X é um tubo de vácuo que converte a energia elétrica em raios-X. A disponibilidade dessa fonte controlável de raios-X criou o campo da radiografia, a imagem de objetos parcialmente opacos com radiação penetrante. Em contraste com outras fontes de radiação ionizante, os raios X são produzidos apenas enquanto o tubo de raios X estiver energizado. Os tubos de raios-X também são utilizados em scanners de tomografia computadorizada, scanners de bagagem de aeroportos, cristalografia de raios-X, análise de materiais e estrutura e para inspeção industrial.
Answer:
You now this question state why a person standing at point Y hears an echo
Answer:
Velocity
Explanation:
Speed does not have a direction, Acceleration means that it is speeding up and not at a constant 15m/h, so the answer is B.
Answer:
F = 196 N
Explanation:
For this exercise we will use Newton's second law, we define a reference system with the x axis in the direction of movement of the stones and the y axis vertically
Y axis
N- W = 0
N = mg
X axis
F -fr = ma
In this case, they ask us for the force to keep moving, so the stones go at constant speed, which implies that the acceleration is zero.
F- fr = 0
F = fr
the friction force has the equation
fr = μ N
fr = μ mg
we substitute
F = μ mg
let's calculate
F = 0.80 9.8 25
F = 196 N