Answer:
<u>because of the doppler effect</u>
Explanation:
<em>Remember</em>, the doppler effect refers to the changes in sound (frequency of sound) observed by a person who is in a position relative to the wave source.
In this example, we notice as the train comes closer to the boy, the sound becomes louder also increasing the pitch slightly, the doppler effect sets in when the train passes the boy because the boy notices a decrease in the pitch of the moving train.
We learn from the change in the observed sound of the train that the frequency of the sound is determined by the distance of the observer from the wave source.
In other words, the closer the source of the sound to the observer; the faster it travels to the observer, however, the farther it is; the lesser it is; the greater the sound heard.
speed of the car = 27 m/s
speed of truck ahead = 10 m/s
relative speed of car with respect to truck

relative deceleration of car

now the distance before they stop with respect to each other is given by



so it will come at the same speed of truck after 20.6 m distance and hence it will not hit the truck as the distance of the truck is 25 m from car
Part b)
Distance traveled by car before it stops is given by



so it will stop after it will cover total 52.1 m distance
Part c)
time taken by the car to stop



now the distance covered by truck in same time

now after the car will stop its distance from the truck is

<em>so the distance between them is 11.5 m</em>
Answer:
a) the oscillation of this field is in phase, when the magnetic field goes in the negative direction of y, the elective field goes in the positive direction of the z axis
b) the direction of the magnetic field perpendicular to this electric field and the speed in the negative x the magnetic field goes in the x direction and in the direction (1, - 1.1)
Explanation:
a) the polarization the determined wave oscillates the electric field, which is the z axis
As the wave travels on the negative x-axis and the magnetic field is perpendicular, this field goes on the positive y-axis
the oscillation of this field is in phase, when the magnetic field goes in the negative direction of y, the elective field goes in the positive direction of the z axis
be) in the case of a polarization in the xi plane the magnetic field must go in the direction of the magnetic field perpendicular to this electric field and the speed in the negative x the magnetic field goes in the x direction and in the direction (1, - 1.1)
Answer:
Option C
The number of microcontinents decreased and the size increased
Explanation:
During the Proterozoic stage, it's expected that while the size of microcontinents increased, the reverse happens on the number to imply the number decreased. Therefore, option C is correct, the number of microcontinents decreased and the size increased
Answer:
h = 599.5 m
Explanation:
Given,
height of structure = 828 m
weight of the tourist = 184 lb
= 184 x 0.45359 = 83.43 Kg
Potential energy = 187000 J
PE = m gd


h = 228.5 m
Height of the room above the ground.
h = 828 - 228.5
h = 599.5 m
Height of the floor above ground is equal to 599.5 m.