Answer: The cake would be 100F after about 47 minutes
Explanation:
Initial temperature = 210F
Time at 140F = 30 minutes
At 140F the cake has lost (210-140)F
= 70F
70F is lost on 30minutes
Rate of temperature reduction
= (70/30) F/min
= 7/3F/min
To lose 110F from 210 to 100F
Temp/time = 7/3
110/t = 7/3
Cross multiply
t = 330/7
t = 47.1429minutes ~ 47min
Force = mass * acceleration
15 = 2.1 * a
a = 15/2.1 = 7.143 m/s^2
Answer:
Approximately
upwards (assuming that
.)
Explanation:
External forces on this astronaut:
- Weight (gravitational attraction) from the earth (downwards,) and
- Normal force from the floor (upwards.)
Let
denote the magnitude of the normal force on this astronaut from the floor. Since the direction of the normal force is opposite to the direction of the gravitational attraction, the magnitude of the net force on this astronaut would be:
.
Let
denote the mass of this astronaut. The magnitude of the gravitational attraction on this astronaut would be
.
Let
denote the acceleration of this astronaut. The magnitude of the net force on this astronaut would be
.
Rearrange
to obtain an expression for the magnitude of the normal force on this astronaut:
.
From wave speed formula, period is 1.96 × 10^-15 seconds per cycle and the frequency is 5.1 × 10^14 Hertz
<h3>
What is Frequency ?</h3>
The frequency of a wave is the number of complete revolution per second made by a vibrating body.
Given that the wavelength of the yellow light from a sodium flame is 589 nm. This light originated from a sodium atom in the hot flame.
(a) In the sodium atom from which this light originated, the period of the simple harmonic motion which was the source of this electromagnetic wave will be found by using the formula
v = λ/T
Where
- v = speed of light = 300,000,000 m/s
- λ = wavelength = 589 × 10^-9 m
Substitute all the parameters
300000000 = 589 × 10^-9/T
T = 589 × 10^-9/300000000
T = 1.96 × 10^-15 seconds per cycle.
(b) The frequency of this light wave is the reciprocal of its period. That is,
F = 1/T
F = 1/1.96 × 10^-15
F = 5.1 × 10^14 Hertz
Therefore, the period of the wave is 1.96 × 10^-15 seconds per cycle and its frequency is 5.1 × 10^14 Hertz
Learn more about Light Wave here: brainly.com/question/10728818
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