Answer:
2.69 m/s
Explanation:
Hi!
First lets find the position of the train as a function of time as seen by the passenger when he arrives to the train station. For this state, the train is at a position x0 given by:
x0 = (1/2)(0.42m/s^2)*(6.4s)^2 = 8.6016 m
So, the position as a function of time is:
xT(t)=(1/2)(0.42m/s^2)t^2 + x0 = (1/2)(0.42m/s^2)t^2 + 8.6016 m
Now, if the passanger is moving at a constant velocity of V, his position as a fucntion of time is given by:
xP(t)=V*t
In order for the passenger to catch the train
xP(t)=xT(t)
(1/2)(0.42m/s^2)t^2 + 8.6016 m = V*t
To solve this equation for t we make use of the quadratic formula, which has real solutions whenever its determinat is grater than zero:
0≤ b^2-4*a*c = V^2 - 4 * ((1/2)(0.42m/s^2)) * 8.6016 m =V^2 - 7.22534(m/s)^2
This equation give us the minimum velocity the passenger must have in order to catch the train:
V^2 - 7.22534(m/s)^2 = 0
V^2 = 7.22534(m/s)^2
V = 2.6879 m/s
Answer:
5. dispersion
6. 49.8°
Explanation:
5. Dispersion is the name given to the phenomenon of light of different wavelengths being bent differently. A rainbow is the result of light from a point source (the sun) being spread out by wavelength (color), a nice example of dispersion.
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6. n = 1.31 is the ratio of the sine of the angle of refraction to the sine of the angle of incidence (for light passing to a medium of n = 1). When the angle of refraction is 90°, the angle of incidence is the "critical angle." So, ...
sin(90°)/sin(critical) = 1.31
critical angle = arcsin(1/1.31) ≈ 49.8°
Answer:
C.) To indicate different versions of the same variable.
Explanation:
Variables in physics often include a subscript. These subscripts are used for indicating different versions of the same variable in physics.
Basically, subscripts are used to represent the beginning (initial) and ending (final) position or point of a variable in physics.
For example, we would look at Gay Lussac' Law of gases.
Gay Lussac law states that when the volume of an ideal gas is kept constant, the pressure of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Gay Lussac's law is given by;
Where;
represents the initial temperature.
represents the initial temperature.
represents the initial pressure.
represents the initial pressure.
Note: 1 and 2 are the subscript while T and P are the variables.
Within the system of the same star, the period of a planet's orbit is
proportional to the 3/2 power of its distance from the central body.
(Kepler's empirical third law of planetary motion, promoted to being
etched in stone by Newton's gravitation.)
(4) ^ 3/2 = <em>8 times</em> as long.
<span> The box is exerting a force of its weight. So we'll use W=mg (Note: you can use the notation F=ma, doesn't matter since weight IS a force.) We can call g negative since it's directed down towards the earth.
</span>
<span>W = 5kg(-9.8 m/(s^2)) = -49 N
</span>
<span>Thus, the box exerts a force of 49N downwards. </span>
