
Actually Welcome to the Concept of the Projectile Motion.
Since, here given that, vertical velocity= 50m/s
we know that u*sin(theta) = vertical velocity
so the time taken to reach the maximum height or the time of Ascent is equal to
T = Usin(theta) ÷ g, here g = 9.8 m/s^2
so we get as,
T = 50/9.8
T = 5.10 seconds
thus the time taken to reach max height is 5.10 seconds.
Answer:
mass = 4kg
Explanation:
Kinetic Energy = 1/2 x m x v²
where m = mass and v = velocity
So,
KE = 50
1/2 × m × 5² = 50
1/2 × m × 25 = 50
m = (50 x 2)/25
m = 100/25
m = 4 kg
Drop "moves" from the list for a moment.
You can also drop "stops moving", because that's included in "changes speed"
(from something to zero).
When an object changes speed or changes direction, that's called "acceleration".
I dropped the first one from the list, because an object can be moving,
and as long as it's speed is constant and it's moving in a straight line,
there's no acceleration.
I think you meant to say "starts moving". That's a change of speed (from zero
to something), so it's also acceleration.
That certain change from that ecosystem will require 50 years or longer because big ecosystems need a long time to restablize the living ecosystem.
Answer:
I think the answer must be A.