a. 46 m/s east
The jet here is moving with a uniform accelerated motion, so we can use the following suvat equation to find its velocity:
where
v is the velocity calculated at time t
u is the initial velocity
a is the acceleration
The jet in the problem has, taking east as positive direction:
u = +16 m/s is the initial velocity
is the acceleration
Substituting t = 10 s, we find the final velocity of the jet:
And since the result is positive, the direction is east.
b. 310 m
The displacement of the jet can be found using another suvat equation
where
s is the displacement
u is the initial velocity
a is the acceleration
t is the time
For the jet in this problem,
u = +16 m/s is the initial velocity
is the acceleration
t = 10 s is the time
Substituting into the equation,
To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. Mathematically it can be described as,
Here,
= Frequency of Source
= Speed of sound
f = Frequency heard before slowing down
f' = Frequency heard after slowing down
v = Speed of the train before slowing down
So if the speed of the train after slowing down will be v/2, we can do a system equation of 2x2 at the two moments, then,
The first equation is,
Now the second expression will be,
Dividing the two expression we have,
Solving for v, we have,
Therefore the speed of the train before and after slowing down is 22.12m/s
The power of the lamp would be calculated with the equation of ohm laws. P = U x I = 122V x 0.1A = 12.2W
Answer:
Thermal energy always flows from the warmer object to the colder object. This causes your hand to get cold, while the ice absorbs your heat and melts.
