Answer: 7200 m
Explanation: The solution is, first convert 15 minutes to seconds.
15 mins x 60 s / 1 min = 900 s
Use the formula for speed which is v= d/t then derive for d.
d = vt
= 8 m/s ( 900s)
= 7200 m
Answer:
5.62 m/s
Explanation:
Newton's law of motion can be used to determine the maximum speed of the elevator. In the question, we are given:
Force exerted by the elevator (R) = 1.7 times the weight of the passenger (m*g)
Thus: R = 1.7*m*g
Distance (s) = 2.3 m
Newton's second law of motion: R - m*g = m*a
1.7*m*g - m*g = m*a
a = 0.7*m*g/m = 0.7*g = 0.7*9.8 = 6.86 m/s²
To determine the maximum speed:
Therefore, the elevator maximum speed is equivalent to 5.62 m/s.
By compressing the spring a distance <em>x</em> (in m), you are storing 1/2 <em>k</em> <em>x</em> ² (in J) of potential energy, which is converted completely into kinetic energy 1/2 <em>m v</em> ², where
• <em>k</em> = 40 N/m = spring constant
• <em>m</em> = 10 kg = mass of the ball
• <em>v</em> = 2 m/s = ball's speed (at the moment the spring returns to its equilibrium point)
So we have
1/2 <em>k</em> <em>x</em> ² = 1/2 <em>m</em> <em>v</em> ²
<em>x</em> = √(<em>m</em>/<em>k</em> <em>v</em> ²) = √((10 kg) / (40 N/m) (2 m/s)²) = 1 m
Answer:
C. f = 440 Hz
Explanation:
- In any wave, there is a fixed relationship between the wavelength (distance between two sucesive crests), the frequency (number of cycles per unit time) and the perturbation speed, as follows:
where v = speed of the wave
λ = wavelength
f = frequency
- Replacing by the givens in (1) and solving for f, we have: