Answer:
(a). The initial velocity is 28.58m/s
(b). The speed when touching the ground is 33.3m/s.
Explanation:
The equations governing the position of the projectile are


where
is the initial velocity.
(a).
When the projectile hits the 50m mark,
; therefore,

solving for
we get:

Thus, the projectile must hit the 50m mark in 1.75s, and this condition demands from equation (1) that

which gives

(b).
The horizontal velocity remains unchanged just before the projectile touches the ground because gravity acts only along the vertical direction; therefore,

the vertical component of the velocity is

which gives a speed
of


Answer:
Civilization's planet is most likely to be doomed because within the next million years the red giant star will possibly supernova.
Explanation:
Civilization's planet is most likely to be doomed because within the next million years the red giant star will possibly supernova. The supernova is the bursting of the star that has reached its end life. This leads to release of massive amount of energy, which can be more than the heat and energy released by the sun.
Answer:
The number of cell phone users increases every year.
Explanation:
Cell phone providers want people to buy cell phones because they make money off of it. The other two options might cause people not to want a cell phone, which could potentially harm their business.
Answer:
what do u need help with
Explanation:
A body of mass m moves along X-axis such that its position co-ordiante at any instant t is x = `at^(4)