a closed system does not allow matter or energy to pass through
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:
7.5 J
Explanation:
To answer the question given above, we need to determine the energy that will bring about the speed of 1 m/s. This can be obtained as follow:
Mass (m) = 15 Kg
Velocity (v) = 1 m/s
Energy (E) =?
E = ½mv²
E = ½ × 15 × 1²
E = ½ × 15 × 1
E = ½ × 15
E = 7.5 J
Therefore, to change the speed to 1 m/s, the employee must do a work of 7.5 J.
<span><em>Continental drift</em> is one of the earliest ways that geologists thought <em>continents</em><span> moved
over time. It is believed in this theory that the Earth’s movement of the
continents are relative to each other.
This idea was subsumed by the plate tectonics theory. Now, what is the
speed of the continental drift?</span></span>
Continental drift speed is 1x 10^-9 m/s.
This is equivalent to a speed of:
1 x 10 ^-9 m/s
= 1 x 0. 000 000 000 1 m/s
= 0. 000 000 000 1 m/s