Answer:
a) During the reaction time, the car travels 21 m
b) After applying the brake, the car travels 48 m before coming to stop
Explanation:
The equation for the position of a straight movement with variable speed is as follows:
x = x0 + v0 t + 1/2 a t²
where
x: position at time t
v0: initial speed
a: acceleration
t: time
When the speed is constant (as before applying the brake), the equation would be:
x = x0 + v t
a)Before applying the brake, the car travels at constant speed. In 0.80 s the car will travel:
x = 0m + 26 m/s * 0.80 s = <u>21 m </u>
b) After applying the brake, the car has an acceleration of -7.0 m/s². Using the equation for velocity, we can calculate how much time it takes the car to stop (v = 0):
v = v0 + a* t
0 = 26 m/s + (-7.0 m/s²) * t
-26 m/s / - 7.0 m/s² = t
t = 3.7 s
With this time, we can calculate how far the car traveled during the deacceleration.
x = x0 +v0 t + 1/2 a t²
x = 0m + 26 m/s * 3.7 s - 1/2 * 7.0m/s² * (3.7 s)² = <u>48 m</u>
Answer:
v = 2,425 m / s
Explanation:
A simple pendulum has anergy stored at the highest point of the path and this energy is conserved throughout the movement.
highest point
Em₀ = U = m g y
lowest point
= K = ½ m v²
Em₀ = Em_{f}
mg y = ½ m v²
v = √ 2gy
let's calculate
v = √ (2 9.8 0.3)
v = 2,425 m / s
Answer:
Some types of electromagnetic waves, like radio waves, microwaves, infrared waves, visible light and ultraviolet waves, can be reflectedSome types of electromagnetic waves, like radio waves, microwaves, infrared waves, visible light and ultraviolet waves, can be reflected
Explanation:
Option D) A drop of mercury is both a pure substance and and element.
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Answer:
1.6 s
Explanation:
To find the time in which the potential difference of the inductor reaches 24V you use the following formula:
V_o: initial voltage = 60V
R: resistance = 24-Ω
L: inductance = 42H
V_L: final voltage = 24 V
You first use properties of the logarithms to get time t, next, replace the values of the parameter:
hence, after 1.6s the inductor will have a potential difference of 24V
