Answer:
1 second
Explanation:
h = −16t² + 32t
When, h = 16
16 = −16t² + 32t
Divide each of the numbers by 16
1 = -1t² + 2t
Rearrange the equation
1t²-2t+1 = 0
Solving by the quadratic formula, we get

So, time taken by the dolphin to jump out of the water and touch the trainer's hand is 1 second.
Answer:
Action force and Reaction force
Explanation:
The action force which is the balanced rock pushing down due to gravity and the reaction force pushing the equal amount of force. These two things are stated in Newtons third law, where he states that "Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first." Also, he states that "all forces acts in pairs," meaning that every force exerted, there is an opposite force on the first.
The net force is the total force. Add 4 and 2 together and you get 6. Since 5 N are pushing against it, you subtract that from 6. The net force is 1 N.
To solve this problem we will apply the concepts related to the conservation of kinetic energy and elastic potential energy. Thus we will have that the kinetic energy is

And the potential energy is

Here,
m = mass
v = Velocity
x = Displacement
k = Spring constant
There is equilibrium, then,
KE = PE

Our values are given as,

Replacing we have that


Therefore the speed of the cart is 2.19m/s
Answer:
Plan B.
Because flexibility is best improved by stretching.
Explanation:
Improving and increasing flexibility is done by having stretching sessions daily which maintains and widens the range of motion in the joints and stretches muscles.