Answer:
Explanation:
<h3>Given Data:</h3>
Mass = m = 68 kg
Velocity = v = 30 m/s
Time = 2 hours = 2 × 60 × 60 = 7200 s
<h3>Required:</h3>
Force = F = ?
<h3>Formula to be used:</h3>
<h3>Solution:</h3>
![\displaystyle F = \frac{(68)(30)}{7200} \\\\F = \frac{2040}{7200} \\\\F = 0.28 N\\\\\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20F%20%3D%20%5Cfrac%7B%2868%29%2830%29%7D%7B7200%7D%20%5C%5C%5C%5CF%20%3D%20%5Cfrac%7B2040%7D%7B7200%7D%20%5C%5C%5C%5CF%20%3D%200.28%20N%5C%5C%5C%5C%5Crule%5B225%5D%7B225%7D%7B2%7D)
Answer:
1.) Frequency F = 890.9 Hz
2.) Wavelength (λ) = 0.893 m
Explanation:
1.) Given that the wavelength = 0.385m
The speed of sound = 343 m / s
To predict the frequency, let us use the formula V = F λ
Where (λ) = wavelength = 0.385m
343 = F × 0.385
F = 343/0.385
F = 890.9 Hz
2.) Given that the frequency = 384Hz
Using the formula again
V = F λ
λ = V/F
Wavelength (λ) = 343/384
Wavelength (λ) = 0.893 m
The two questions can be solved with the use of formula
The only vertical forces are weight and normal force, and they balance since the surface is horizontal. The horizontal forces are the applied force (uppercase F) in the direction the block slides and the frictional force (lowercase f) in the opposite direction.
Apply Newton's 2nd Law in the horizontal direction:
ΣF = ma
F - f = ma
where f = µmg
F - µmg = ma
F = m(a +µg)
F = (20 kg)(1.4 m/s² + 0.28(9.8 m/s²)
F = 83 N
Answer:
D. has no overall force acting on it.
Explanation:
Why?
Because in a straight line at the constant speed means the car moving in the same velocity, which is not acceleration neither deceleration, and it cannot be on a downhill slope. So the correct answer is
<h3>→ D. has no overall force acting on it.</h3>
Answer:
Explanation:
Power (p)= 40 watt
time (t)= 3 minutes = 180 seconds
Energy (E)= ?
we know
P = E/t
40 = E / 180
E = 7200 Joules
Therefore it does 7200 joules of work.
hope it helps :)
