The color can be determined by either the frequency or the amplitude. The amplitude is the maximum height of the wave, while frequency is the number of cycle (amplitude to amplitude) per second. <em>Thus, the answer would be: the amplitude of the wave.</em>
Answer:
Explanation:
a )
change in the gravitational potential energy of the bear-Earth system during the slide = mgh
= 45 x 9.8 x 11
= 4851 J
b )
kinetic energy of bear just before hitting the ground
= 1/2 m v²
= .5 x 45 x 5.8²
= 756.9 J
c ) If the average frictional force that acts on the sliding bear be F
negative work done by friction
= F x 11 J
then ,
4851 J - F x 11 = 756.9 J
F x 11 = 4851 J - 756.9 J
= 4094.1 J
F = 4094.1 / 11
= 372.2 N
Answer:
A) The work done by the engine is: 6.8MJ/L
B) The fuel efficiency is
Explanation:
A)
We know that the gasoline releases about 3.4*10^7 J of energy for each liter, and about 80% of that energy is lost as heat; it means that the other 20% of the energy released is taken for the engine to do work. In that sense, the work done by the engine is 20% of the 3.4*10^7 J that the gasoline releases for 1 liter, so:
This last can be seen as a conversion factor, where we multiply the energy released by the gasoline by the factor (20 J taken for do work for each 100 J released).
B) We know that the car requires 5.9*10^5 J of work <u>for each km traveled</u>. That is the energy that the car requires, but it is not the energy that you have to give to the car; take in mind that the energy that you put in the car in gasoline liters will be not taken all, but just 20%. Also we know that the work done by the engine for 1 liter of gasoline is 6.8MJ, and that is just the work taken for do work (the useful energy), so we can connect both data:
The first fraction, is the ratio or the proportion of (1 km requieres 5.9*10^5 J); and we multiply by the second fraction , which is the ratio: 6.8*10^6 J of work done for each liter of gasoline.
Answer:
The speed of this particle is constantly .
Explanation:
Position vector of this particle at time :
.
Write as a column vector to distinguish between the components:
.
Both and are constants. Therefore, and would also be constants with respect to . Hence, and .
Differentiate (component-wise) with respect to time to find the velocity vector of this particle at time :
.
The speed (a scalar) of a particle is the magnitude of its velocity :
.
Therefore, the speed of this particle is constantly (a constant.)