Correct question is;
A frog leaps straight up from the ground and is caught when he reaches his maximum height 2 seconds later by a little girl. We want to find the vertical velocity of the frog at the moment that it left the ground. Which kinematic formula would be most useful to solve for the target unknown? Assume the positive direction is upward and air resistance is negligible.
Answer:
v = u + at
Explanation:
We are given time taken to reach maximum height to be 2 seconds.
We also know that since it's going upwards against gravity, our acceleration due to gravity will be g = -9.8 m/s²
Now, since we have values of g and t and we know that at maximum height vertical component of velocity is zero.
Thus, we can use Newton's first equation of motion to solve for the vertical velocity at which it left the ground.
Thus;
v = u + at
Where v is velocity at maximum height and u is velocity at which it left the ground.
