(a) The skater covers a distance of S=50 m in a time of t=12.1 s, so its average speed is the ratio between the distance covered and the time taken:

(b) The initial speed of the skater is

while the final speed is

and the time taken to accelerate to this velocity is t=2 s, so the acceleration of the skater is given by

(c) The initial speed of the skater is

while the final speed is

since she comes to a stop. The distance covered is S=8 m, so we can use the following relationship to find the acceleration of the skater:

from which we find

where the negative sign means it is a deceleration.
Work = (500N)(15m)=7500J Power= (7500J)/(20s) =375 W
Hopefully this helps
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Learn more about The potential problems here:-brainly.com/question/21836542
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Answer:
The phase angle is 0.0180 rad.
(c) is correct option.
Explanation:
Given that,
Voltage = 12 V
Angular velocity = 50 Hz
Capacitance 
Inductance 
Resistance 
We need to calculate the impedance
Using formula of impedance



We need to calculate the phase angle
Using formula of phase angle



Hence, The phase angle is 0.0180 rad.
Saludos!
Respuesta:28,64 m/s.
Explicación:Datos:
Altura o distancia recorrida: 40 m
Vo: 6 m/s
Aceleración de la gravedad: 9,81 m/s²
El ejercicio puede ser resuelto facilmente utilizando la siguiente formula, sin embargo es posible realizarlo utilizando formulas diferentes.
Entonces tenemos que:

Es importante saber que al estar lanzando el ladrillo hacia abajo, el sentido del movimiento sigue el sentido de la gravedad, es decir es necesario que tomes el valor de la gravedad como positivo (+) y no negativo (-) como normalmente se usa.
Sustituyendo tenemos que:

Que tengas un buen día!