Answer:
50 J
Explanation:
The net force acting on the box is given by the algebraic sum of the two forces, so:
The net work done on the box is equal to (assuming the net force is parallel to the displacement of the object)
where
F = 5 N is the net force on the object
d = 10 m is the displacement of the object
Substituting,
Answer:
The correct answer is the third option: The kinetic energy of the water molecules decreases.
Explanation:
Temperature is, in depth, a statistical value; kind of an average of the particles movement in any physical system (such as a glass filled with water). Kinetic energy, for sure, is the energy resulting from movement (technically depending on mass and velocity of a system; in other words, the faster something moves, the greater its kinetic energy.
Since temperature is related to the total average random movement in a system, and so is the kinetic energy (related to movement through velocity), as the thermometer measures <u>less temperature</u>, that would mean that the particles (in this case: water particles) are <u>moving slowly</u>, so that: the slower something moves, the lower its kinetic energy.
<u>In summary:</u> temperature tells about how fast are moving and colliding the particles within a system, and since it is <em>directly proportional</em> to the amount of movement, it can be related (also <em>directly proportional</em>) to the kinectic energy.
(6) first choice: the frequency appears higher and wavelength is shorter.
The car approaches a stationary observer and so the sound will appear to have shorter wavelength. This creates an effect of its siren to sound with higher frequency than it would do if both were stationary.
(7) The Doppler formula for frequency in the case of a stationary observer and source approaching it is as follows:
The wavelength is then
The third choice "0.80m; 431Hz" is correct
Answer:
c
Explanation:
betweeb the north american and eurasian planes
<span>a) 1960 m
b) 960 m
Assumptions.
1. Ignore air resistance.
2. Gravity is 9.80 m/s^2
For the situation where the balloon was stationary, the equation for the distance the bottle fell is
d = 1/2 AT^2
d = 1/2 9.80 m/s^2 (20s)^2
d = 4.9 m/s^2 * 400 s^2
d = 4.9 * 400 m
d = 1960 m
For situation b, the equation is quite similar except we need to account for the initial velocity of the bottle. We can either assume that the acceleration for gravity is negative, or that the initial velocity is negative. We just need to make certain that the two effects (falling due to acceleration from gravity) and (climbing due to initial acceleration) counteract each other. So the formula becomes
d = 1/2 9.80 m/s^2 (20s)^2 - 50 m/s * T
d = 1/2 9.80 m/s^2 (20s)^2 - 50m/s *20s
d = 4.9 m/s^2 * 400 s^2 - 1000 m
d = 4.9 * 400 m - 1000 m
d = 1960 m - 1000 m
d = 960 m</span>
