EjerciciosFyQ

Kinetic energy of a moving projectile (8317)

F_y_Q — 2024-09-19T04:20:43Z

Calculate the kinetic energy of an 18 g projectile moving horizontally at .

If you observe the units in the problem statement, you will see that the mass is not expressed in the SI unit of mass. The first thing you need to do is convert it to kg to make the problem homogeneous.

The kinetic energy of the projectile is given by the equation:

You know the necessary data, so you just need to substitute and calculate:

Efficiency and useful power (8300)

F_y_Q — 2024-09-07T03:10:02Z

A motor is supplied with a power of 1 000 W. If the efficiency of this motor is , calculate the useful power and the lost power.

Efficiency or performance is the ratio between the useful power and the supplied power:

The useful power will be:

The lost power will be the difference between the supplied and the used power:

Heat transfer (3776)

F_y_Q — 2016-10-18T12:50:31Z

Is there heat transfer between two bodies with different temperatures when they are put in contact?

- Energy / Heat, Energy transfer, Conduction, SOLVED

Mass of iron in a heat transfer (3589)

F_y_Q — 2016-05-28T07:34:08Z

What mass of iron would require 1 450 cal of energy to raise its temperature by ?

The specific heat of iron is

To find the mass, use the formula:

Rearrange the equation to solve for mass:

Kinetic energy of an object (3440)

F_y_Q — 2016-01-02T04:58:14Z

An object with a mass of 2 kg is falling at a speed of . What is the kinetic energy of this object?

The equation for kinetic energy is:

Heat transfer in fluids (2909)

F_y_Q — 2015-01-05T05:55:41Z

How is heat transferred in the air?

Heat is transferred in a fluid (liquids or gases) by convection, which involves the movement of matter. This means that higher temperature air moves from one point to another until the system reaches the thermal equilibrium.

Matching terms: types of energy and systems (2733)

F_y_Q — 2014-10-10T03:59:25Z

Define, in your own words, what energy is and provide two examples of systems; one with kinetic energy and another with gravitational potential energy. Match the terms to these two groups (letter-number):
a) Combustion of diesel ; b) Friction between a match and sandpaper ; c) A bee flying ; d) A plane that took off a minute ago ; e) A pole when it is completely bent.
1) Kinetic energy ; 2) Elastic potential energy ; 3) Mechanical energy ; 4) Chemical energy ; 5) Internal energy

- Energy / Types of energy, SOLVED

Energy transformations (1929)

F_y_Q — 2012-11-07T21:24:34Z

What type of energy is involved in each of the following situations?

a) Wood is burning in the fire.

b) A radio station is broadcasting its usual program. Waves are coming out of its antenna.

c) A mobile phone is playing music.

a) Internal energy is converted into heat energy.

b) Electromagnetic energy is converted into acoustic energy.

c) Chemical energy is converted into electrical energy.

Definition of energy (1928)

F_y_Q — 2012-11-07T21:24:29Z

Define, with your own words, what energy is. Explain three different types of energy.

Energy is the ability of a system to cause changes in other systems or in itself.

a) Kinetic energy. The energy possessed by an object due to its motion.

b) Potential energy. The energy sotred in an object due to its position or state.

c) Thermal energy. The energy that comes from the temperature of an object, which is the total kinetic energy of its particules.