Answer:
The correct answer is A. Vibration.
Explanation:
Mechanical waves is formed by the oscillation of matter and therefore transfer energy from one medium to the other. Unlike electromagnetic waves, mechanical waves need some medium to propagate. It requires an initial energy input and thus carries this energy when it propagates. There are three types of mechanical waves namely transverse waves, longitudinal waves and surface waves. Examples of such waves are sound waves, water waves and seismic waves.
If there is no current in the wire .....the direction of magnetic field remains unchanged
You'll never get the correct answer without the correct conversion factor. Note carefully that you have no decimal. It should be
<span>1 km = 0.6214 miles </span>
<span>1000 m = 1 km </span>
<span>60 seconds = 1 minute </span>
<span>60 minutes = 1 hour. </span>
<span>2.998E8 m/s x (1 km/1000m) x (0.6214 miles/km) x (60 sec/min) x (60 min/hr) = ?</span>
Yep that's correct
And transverse waves move perpendicular to the direction of energy transport
Answer:
A. 231.77 J
B. 5330.71 J
C. 46 donuts
Explanation:
A. To lift the barbell once, she will have to extend it the full length of her arm. The work done will then be:
W = F * d
Where the force is the weight of the barbell.
F = m * g
Hence, the work done in lifting the barbell is:
W = m * g * d
W = 43 * 9.8 * 0.55
W = 231.77 J
B. If she does 23 repetitions, the total energy she expend will be equal to the Potential energy when the barbell is lifted multiplied by 23:
E = 23 * m * g * d
E = 23 * 231.77
E = 5330.71 J
C. 1 Joule = 4.184 calories
5330.71 Joules = 5330.71 * 4.184 = 22303.69
If 1 donut contains 490 calories, the number of donuts she will need will be:
N = 22303.69/490 = 45.5 donuts or 46 donuts
