Answer:
2856.96 J
0
0

6.78822 m/s
Explanation:
= Initial velocity = 9.6 m/s
g = Acceleration due to gravity = 9.81 m/s²
h = Height
The athlete only interacts with the gravitational potential energy. Air resistance is neglected.
At height y = 0
Kinetic energy

At height y = 0 the potential energy is 0 as

At maximum height her velocity becomes 0 so the kinetic energy becomes zero.
As the the potential and kinetic energy are conserved
The general equation

Half of maximum height



The velocity of the athlete at half the maximum height is 6.78822 m/s
Answer:
0 Newtons
Explanation:
The velocity of the object does not change, it is a constant 54 km/hr. When velocity does not change, acceleration is zero. Using the formula Force = mass x acceleration, we find:
mass = 1200 kg
acceleration = 0
F = (1200)(0) = 0
Negative charge (it has more protons than electrons)
So that international people don't mistake units for others. ex 1 inch could be mistaken for 1 cm in non American countries