Wow! 2.95m/s is a mighty fast pace for a backpacker. Must have one of those Star Wars anti-gravity packs. Also, I would be curious as to why she passed her destination and then walked back.
<span>Anyway, it goes like this: </span>
<span>Say the time walking east is 't', and the total time is 'T'. </span>
<span>Then 5340 m + .511 t = 1.43 T </span>
<span>(This assumes that velocity is positive in both directions) </span>
<span>Two unknowns in one equation. But you also know that the time spent walking west is </span>
<span>5340m/ 2.95m/s = 1810 sec. </span>
<span>and the total time T = 1810 +t </span>
<span>Substitute this into the first equation, and you can solve for t = 3092 sec. </span>
<span>Then T = 4902 sec. and distance walked east is .511t = 1580m.</span>
Answer:
359 m/s
Explanation:
Highest frequency a person can hear is 20,000Hz.
f = c × λ
Frequency = Wave speed × Wavelength
Wavelength = 20,000 ÷ 343 = 58.31m
Wavespeed = Frequency ÷ Wavelength
c = 20,950 ÷ 58.31 = 359.3 m/s
= 359 m/s (3 s.f.)
(a) The kinetic energy of the projectile when it reaches the highest point in its trajectory is 900 J.
(b) The work done in firing the projectile is 2,500 J.
<h3>
Kinetic energy of the projectile at maximum height</h3>
The kinetic energy of the projectile when it reaches the highest point in its trajectory is calculated as follows;
K.E = ¹/₂mv₀ₓ²
where;
- m is mass of the projectile
- v₀ₓ is the initial horizontal component of the velocity at maximum height
<u>Note:</u> At maximum height the final vertical velocity is zero and the final horizontal velocity is equal to the initial horizontal velocity.
K.E = (0.5)(2)(30²)
K.E = 900 J
<h3>Work done in firing the projectile</h3>
Based on the principle of conservation of energy, the work done in firing the projectile is equal to the initial kinetic energy of the projectile.
W = K.E(i) = ¹/₂mv²
where;
- v is the resultant velocity
v = √(30² + 40²)
v = 50 m/s
W = (0.5)(2)(50²)
W = 2,500 J
Thus, the kinetic energy of the projectile when it reaches the highest point in its trajectory is 900 J.
The work done in firing the projectile is 2,500 J.
Learn more about kinetic energy here: brainly.com/question/25959744
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Because the molecules that move freely begin to compact closer together, with less heat, means less molecular activity.
