Answer;
= 60 m
Explanation;
s = 80 m
= ½at² = ½ * 9.8m/s² * t² → t = 4.04 s
At any time 0 ≤ t ≤ 4.04 s, height is
y = Yo + ½at² = 80 m - 4.9m/s² * t²
so at t = 4.04s/2 = 2.02 s,
y = 80 m - 4.9m/s² * (2.02s)² = 60 m
(so it drops 15 m during the first 2.02 s and 60 m during the second 2.02 s)
Kinetic energy = 1/2 mv²
so, you will have to do it for every single one of them if you want steps.
Kinetic Energy = For A, 202500J
For B, 90000J
For C, 168750J
For D, 75000J
From the above we an say that kinetic energy is highest in option A.
In case, there are no steps needed, just by the values we are able to understand the answer as in Option A, eventhough the mass is the same, higher the velocity or speed, higher the kinetic energy
The answer is 45 degrees.
According to the Kinematics of projectile motion, if the purpose is to maximize range, optimum angle of landing is always 45 degrees.If the purpose is to maximize range & projection height is zero, the optimum angle of projection (and landing) is 45 degrees.
Then the magnitude of the net force is the difference between the two forces,
and its direction is the same as the direction of the greater one.
