Which statement best describes the energy changes that occur while a child is riding on a sled down a steep, snow-covered hill?
1 answer:
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Answer:
E= 50.1*10³ N/C
Explanation:
Assuming no other forces acting on the electron, if the acceleration is constant, we can use the following kinematic equation in order to find the magnitude of the acceleration:
We know that v₀ = 0 (it starts from rest), that vf = 0.1*c, and that x = 0.051 m, so we can solve for a, as follows:
According to Newton's 2nd Law, this acceleration must be produced by a net force, acting on the electron.
Assuming no other forces present, this force must be due to the electric field, and by definition of electric field, is as follows:
F = q*E (1)
In this case, q=e= 1.6*10⁻19 C
But this force, can be expressed in this way, according Newton's 2nd Law:
F = m*a (2) ,
where m= me = 9.1*10⁻³¹ kg, and a = 8.8*10¹⁵ m/s², as we have just found out.
From (1) and (2), we can solve for E, as follows:
⇒ E = 50.1*10³ N/C
<h3><u>Complete Question </u></h3>
Q)Two loudspeakers, A and B, are driven by the same amplifier as shown and emit sinusoidal waves in phase. Speaker B is 2.00 m to the right of speaker A. Consider point Q along the extension of the line connecting the speakers, 1.00 m to the right of speaker B. Both speakers emit sound waves that travel directly from the speaker to point Q. a) What is the lowest frequency for which constructive interference occurs at point Q? b) What is the lowest frequency for which destructive interference occurs at point Q? The speed of sound wave is 344 m/s.
Answer:
lowest frequency is 172 Hz. for n = 1
lowest frequency is 86 Hz for n = 0
Explanation:
(a) Constructive interference takes place when the path difference is n where n=1,2,3 ...
frequency f = v /λn
= v n / d
= n ( 344 / 2 )
= n ( 172 ) Hz.
lowest frequency is 172 Hz
b)Destructive interference takes place when the path difference is n/2 x where n=1,3,5 ...
λ = 4/2n+1
for n = 0
λ = 4m
f = 344/4
f = 86 Hz.
lowest frequency is 86 Hz