Answer:
The parachuter is falling at a speed of 31.667 meters per second.
Explanation:
Given that parachuter falls at constant speed and travelled distance and time are known, the unknown is speed, measured in meters per second, which is obtained by the following kinematic expression:
Where:
- Travelled distance, measured in meters.
- Time, measured in seconds.
If and
, the speed of the parachuter is:
The parachuter is falling at a speed of 31.667 meters per second.
The skateboarder will have the greatest potential energy at point <em>G.</em>
Potential energy is the energy possessed by a body by virtue of its position. The gravitational potential energy of a body is given by the expression,
Here, <em>m</em> is the mass of the body, <em>g</em> the acceleration due to gravity and <em>h</em> is the height of the body from the ground.Thus as <em>h</em> increases, the potential energy increases.
From the figure, it can be seen that the highest point in the skateboarder's trajectory is <em>G.</em> hence, he would have the highest potential energy at the point <em>G.</em>
Given that,
A ball is thrown upward. At a height of 10 meters above the ground, the ball has a potential energy of 50 Joules. It is moving upward with a kinetic energy of 50 Joules.
We need to find the maximum height h reached by the ball. Let at a height of 10 meters, it has a potential energy of 50 Joules. So,
........(1)
Let at a height of h m, it reaches to a maximum height. at this point, it has a total of 100 J of energy. So,
So, the correct option is (E) "h = 20 m".