I think it’s when the sun explodes because since we need to the sun I think the human population will fall out. also a huge war, a meteoroid huge as the one that killed the dinosaurs comes down, there is so much ways on how the human population can stop growing. hope this help at least!
Answer:
it goes up until we help it to but the moment we stop support it gets affected by gravity and goes back
Explanation:
Answer:
(a). 19.0 m/s
(b). 9.5m/s
Explanation:
Assuming speed of sound is 343m/s.
(a).
As the train approaches, from the the Doppler equation we have
solving for we get:
.
And as the train cuts its speed in half, the equation gives
substituting the value of we get:
or 68.6 km per hour, which is the speed of the train before slowing down.
(b).
The speed of the train after slowing down is half the previous speed; therefore,
or 34.3 km per hour.
A. Just plug it in..............