B. Let me know if that was correct :)
By definition, the wavelength of an electromagnetic wave is calculated using the following formula:
Where:
\lambda = wavelength
c = speed of light =
f = frequency of the wave.
This relation means that the division of the wavelength λ between the frequency f is always equal to the speed of light.
Thus:
the velocity v of this wave must be equal to c.
Finally the correct answer is D.
Explanation:
Work cannot be increased by using a machine of some kind.
Answer:
Choice a. 1 kg, assuming that all other forces on the object (if any) are balanced.
Explanation:
By Newton's Second Law,
,
where
- is the acceleration of the object in ,
- is the net force on the object in Newtons, and
- is the mass of the object in kilograms.
As a result,
.
Assume that all other forces on this object are balanced. The net force on the object will be . The net force is constant. Acceleration should also be constant and the same as the average acceleration in the two seconds.
<h3>What is the
average acceleration of this object?</h3>
.
.
<h3>Apply Newton's Second Law to find the mass of the object.</h3>
.
(1) The time taken for the drag racer to accelerate is 4.89 s
(2) The speed of the contestant (a) in feet per second is 30.89 ft/s (b) in miles per hr is 21.12 miles per hr.
(1) To calculate the time required to accelerate 18 ft/sec² from rest to a velocity of 60 mph, we use the formula below.
Formula:
- t = (v-u)/a........... Equation 1
Where:
- t = time
- v = Final velocity
- u = initial velocity
- a = acceleration.
From the question,
Given:
- a = 18 ft/sec² = (18×0.3048) = 5.4864 m/s²
- v = 60 mph = (60×0.44704) = 26.82 m/s
- u = 0 m/s ( from rest)
Substitute these values into equation 1
- t = (26.82-0)/5.4864
- t = 4.89 seconds
(2) To calculate the speed of the contestant, we use the formula below
Formula:
- s = d/t............ Equation 1
Where:
- s = speed of the contestant
- d = distance
- t = time.
From the question,
Given:
Substitute these values into equation 1
(a) In feet = (9.43/0.3048) = 30.94 ft/s
(b) in miles per hr = (9.43×2.24) = 21.12 miles per hr
Hence, (1) The time taken for the drag racer to accelerate is 4.89 s (2) The speed of the contestant (a) in feet per second is 30.89 ft/s (b) in miles per hr is 21.12 miles per hr.
Learn more about speed here: brainly.com/question/4931057