An object is falling from a height of 7.5 meters. At what height will its velocity be 7 meters/second?
1 answer:
Answer:
5.0 m
Explanation:
The velocity of the object at time t is given by
where a=9.8 m/s^2 is the acceleration of gravity and t is the time. If we substitute v=7 m/s, we can find the time t at which the velocity became 7 m/s:
The height of the object at time t, h(t), is given by the equation
where is the initial height. By substituting t=0.71 s inside the equation, we find the height h(t) at which the velocity is 7 m/s:
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Answer:
5.3 x 10⁻⁹ C
Explanation:
r = radius of cylindrical shell = 10⁻⁵ m
L = length = 0.32 m
A = area
Area is given as
A = 2πrL
A = 2 (3.14) (10⁻⁵) (0.32)
A = 20.096 x 10⁻⁶ m²
d = separation = 10⁻⁸ m
= dielectric constant = 4
Capacitance is given as
eq-1
V = Potential difference across the membrane = 74 mV = 0.074 Volts
Q = magnitude of charge on each side
Magnitude of charge on each side is given as
Q = CV
using eq-1
Inserting the values
Q = 5.3 x 10⁻⁹ C
Answer:
t = 6 [s]
Explanation:
In order to solve this problem we must first use this equation of kinematics.
where:
Vf = final velocity = 0 (the car comes to rest)
Vo = initial velocity = 72 [km/h]
a = acceleration [m/s²]
x = distance = 60 [m]
First we must convert the velocity from kilometers per hour to meters per second.
Now using this other equation of kinematics.
0 = 20-3.33*t
t = 6[s]