How much metabolic energy is required for a 68 kg person to run at a speed of 15 km/h for 18 min ? Assume that metabolic power o

Umnica [9.8K]

Answer:

Potential energy is the energy that exists by virtue of the relative positions (configurations) of the objects within a physical system.

This form of energy has the potential to change the state of other objects around it, for example, the configuration or motion.

Various forms of energy can be grouped as potential energy.

Each of these forms is associated with a particular kind of force acting in conjunction with some physical property of matter (such as mass, charge, elasticity, temperature etc).

For example, gravitational potential energy is associated with the gravitational force acting on object's mass; elastic potential energy with the elastic force (ultimately electromagnetic force) acting on the elasticity of a deformed object; electrical potential energy with the coulombic force; strong nuclear force or weak nuclear force acting on the electric charge on the object; chemical potential energy, with the chemical potential of a particular atomic or molecular configuration acting on the atomic/molecular structure of the chemical substance that constitutes the object; thermal potential energy with the electromagnetic force in conjunction with the temperature of the object.

For an example of gravitational potential energy, consider a book placed on top of a table.

To raise the book from the floor to the table, work must be done, and energy supplied. (If the book is lifted by a person then this is provided by the chemical energy obtained from that person's food and then stored in the chemicals of the body.) Assuming perfect efficiency (no energy losses), the energy supplied to lift the book is exactly the same as the increase in the book's gravitational potential energy.

The book's potential energy can be released by knocking it off the table.

As the book falls, its potential energy is converted to kinetic energy.

When the book hits the floor this kinetic energy is converted into heat and sound by the impact.

Explanation:

4 0

3 years ago

Read 2 more answers

This is for physical science, need help :/

marusya05 [52]

1). From the frame of reference of a passenger on the airplane looking out of his window, the tree appears to be moving, at roughly 300 miles per hour toward the left of the picture.

2). The SI unit best suited to measuring the height of a building is the meter.

3). 'Displacement' is the straight-line distance and direction from the start-point to the end-point, regardless of the path that was followed to get there.

The ball started out in the child's hand, and it ended up 2 meters away from her in the direction of the wall. So the displacement of the ball from the beginning to the end of the story is: 2 meters toward the wall.

6 0

3 years ago

Từ độ cao h=2m một vật bắn lên với vận tốc ban đầu V0=10(m/s), hợp với phương ngang 1 góc 30 độ.Hãy xác minh

nydimaria [60]

Answer:

A IS THE ANSWER

Explanation:

HOPE IT HELPS AND PLEASE MARK AS BRAINLIST

8 0

3 years ago

A speed boat increases its speed uniformly from vi = 20.0 m/s to vf = 30.0 m/s in a distance of 2.00 x 10^2m. (a) Draw a coordin

pychu [463]

a) See graph in attachment

b) The suvat equation to use is $v_f^2 - v_i^2 = 2as$

c) The acceleration is $a=\frac{v_f^2-v_i^2}{2s}$

d) The acceleration is $1.25 m/s^2$

e) The time needed is 8 s

Explanation:

a)

For this part, find in attachment the diagram representing this situation.

Since we are not given any particular direction for the motion, we choose the x-direction as the direction of motion of the boat.

Then we have the following:

- The initial position of the boat is $x_i = 0$ , the origin

- The final position of the boat is $x_f = 200 m$

- The initial velocity of the boat is $v_i = 20.0 m/s$

- The final velocity of the boat is $v_f = 30.0 m/s$

Note that the arrow representing the final velocity is longer than that of the initial velocity, since the final velocity is larger.

b)

The motion of the speed boat is a uniformly accelerated motion (motion at constant acceleration), therefore we can use one of the suvat equations. In this particular problem, we know the following quantities:

$v_i = 20.0 m/s$ , the initial velocity

$v_f = 30.0 m/s$ , the final velocity

$s = x_f - x_i = 200 m$ , the displacement of the boat