F=MA
F=(8 kg)(9.8 m/s)
F= 78.4 N
W=FD
W=(78.4 N)(7 m)
W=548.8 J
How this helps
Trick question? In order to have kinetic energy, an object must be moving. Therefore, in this case, kinetic energy would be 0. If it were asking about potential energy, it would be a different story.
Scientific Method: Because, they use their method which the scientific one to solve investigations.
Answer: 0.42 Amperes
Explanation:
Given that:
Current, I = ?
Electric charge Q = 100 coulomb
Time, T = 4.0 minutes
(The SI unit of time is seconds. so, convert 4.0 minutes to seconds)
If 1 minute = 60 seconds
4.0 minutes = 4.0 x 60 = 240 seconds
Since electric charge, Q = current x time
i.e Q = I x T
100 coulomb = I x 240 seconds
I = 100 coulomb / 240 seconds
I = 0.4167 Amperes (round to the nearest hundredth which is 0.42 amperes)
Thus, 0.42 Amperes of current flows in the circuit.
To develop this problem it is necessary to apply the oscillation frequency-related concepts specifically in string or pipe close at both ends or open at both ends.
By definition the oscillation frequency is defined as
Where
v = speed of sound
L = Length of the pipe
n = any integer which represent the number of repetition of the spectrum (n)1,2,3...)(Number of harmonic)
Re-arrange to find L,
The radius between the two frequencies would be 4 to 5,
Therefore the frequencies are in the ratio of natural numbers. That is
Here f represents the fundamental frequency.
Now using the expression to calculate the Length we have
Therefore the length of the pipe is 1.3m
For the second harmonic n=2, then
Therefore the length of the pipe in the second harmonic is 2.6m