An electric motor uses 80 J of energy to lift a mass of 1.8 kg a vertical distance of 2 m. Calculate the efficiency of the machine. Use 10 m/s² for gravity

The process of refraction of light​ occurs when light rays bends when travelling between media of different densities.

What is refraction of light?

Refraction of light is the bending of light rays or the change in the direction of light rays as it travels between media of different densities.

Light waves travel faster in media of less density than media of more density.

The change in density of the media makes light waves to be bend towards or away from the normal.

For example, when light travels from less dense air to more dense water, the light rays are bent towards the normal. However, when light rays travel from water to air, the light rays are refracted away from the normal.

In conclusion, refraction of light waves occur when light crosses the boundary of media of different densities.

Learn more about refraction of light at: https://brainly.com/question/27932095

#SPJ1

The force support B must exert on the beam in order for it to remain at rest is equal to the sum of the forces caused by the beam's weight (mg) and the worker's weight (mw).

Force is a physical quantity that is used to describe an interaction between two objects. It is a vector quantity, meaning that it has both magnitude and direction. Force can cause an object to accelerate, decelerate, change shape, or even change direction. It is a measure of how much energy is transferred between two objects, and can be calculated using the equation: Force = mass x acceleration.

For equilibrium, the sum of the forces must be zero. Therefore, the force Support B must exert on the beam is equal to the sum of the forces acting on the beam, which can be expressed as FB = g(xmW/L + mB/2). Here, g is the acceleration due to gravity, mW is the mass of the worker, mB is the mass of the beam, and L is the length of the beam.

To learn more about force
https://brainly.com/question/12785175
#SPJ4

Answer:

Thermal

Explanation:

Hooke's Law can be given as follows sometimes:

The restoring force of a spring is equal to the spring constant multiplied by the displacement from its normal position:

F = -kx

Where, F = Restoring force of a spring (Newtons, N)

k = Spring constant (N/m)

x = Displacement of the spring (m)

The negative sign relates to the direction of the applied force and by convention, the minus or negative sign is present in F = -kx. The restoring force F is directly proportional to the displacement (x), according to Hooke's law. When the spring is compressed, the displacement (x) is negative. It is zero when the spring is at its original length and positive when the spring is extended.

Practically, Hooke's Law is applicable only within a limited frame of reference, and through experimenting, this statement proves to be true. Because materials cannot be compressed beyond a certain size or expanded beyond a certain size without some permanent deformation or change of their original state.

The law only applies under some conditions such as a limited amount of force or deformation. Factually, many materials will noticeably deviate from Hooke's law even before those elastic limits are reached.

To know more about Hooke's law, visit :

https://brainly.com/question/15365772

Answer:

Vector

Explanation:

Vector is a quantity that shows the direction or path through which a body travels with as it changes position.

As body travels, the direction sometimes changes and this is described by the vector of the body.

Velocity is a vector quantity that describes the displacement per unit of time of a body.

Speed is a scalar that deals with the distance covered per time

So, a vector specifies the magnitude of a physical quantity and also the direction through which it travels.

a)

Buoyant force varies directly with the density, volume and mass of the displaced fluid. According to Archimedies principle, the buoyant force equals the weight of fluid displaced. The lead sphere has more weight than the aluminium sphere. This means that it would displace more fluid. Thus, the lead sphere experiences a greater buoyant force

b) The buoyant force is is also affected by the type of fluid. Different fluids have different densities. If the density of the object is greater than the density of the fluid, it tends to sink. Thus, the answer is Yes

The mass of Car B is -6000 kg.

To solve this problem, we can apply the principle of conservation of momentum, which states that the total momentum before the collision is equal to the total momentum after the collision.

Therefore, we can write the equation for the conservation of momentum as:

(mass of Car A * velocity of Car A) + (mass of Car B * velocity of Car B) = (mass of Car A + mass of Car B) * velocity after collision

Let's substitute the given values into the equation:

(2000 kg * 10 m/s) + (mass of Car B * 0 m/s) = (2000 kg + mass of Car B) * (-5 m/s)

Simplifying the equation:

20000 kg*m/s = -5 m/s * (2000 kg + mass of Car B)

Dividing both sides by -5 m/s:

-4000 kg = 2000 kg + mass of Car B

Subtracting 2000 kg from both sides:

mass of Car B = -4000 kg - 2000 kg

mass of Car B = -6000 kg

know more about momentum here:

https://brainly.com/question/30487676

#SPJ8

False. The potential energy of the crate is not mgd, but rather the work done by the force f in moving the crate a distance d is equal to the change in potential energy of the crate, according to the work-energy theorem.

This means that the potential energy of the crate increases by an amount equal to the work done by the force f.

The work done by the force f is equal to the product of the force and the distance moved in the direction of the force, or W = fd. The change in potential energy is equal to the product of the mass, the acceleration due to gravity, and the change in height, or ΔPE = mgh. In this case, however, the crate is moved horizontally, so there is no change in height, and the potential energy does not depend on the work done to move it a distance d.

Therefore, the correct expression for the change in potential energy of the crate is ΔPE = 0. If there is no vertical motion or change in height, the potential energy of the object remains constant, and the work done by the force f is purely kinetic energy, which is equal to \(1/2mv^2\) .

Learn more about potential energy :

https://brainly.com/question/24284560

#SPJ4

Answer:

Only magnetic field present

Explanation:

Since, the positively charged particle does not speed up or slow down, but it does deflect in the downward direction.  This means only magnetic field is present.

This is because electric field changes the velocity and magnetic field changes the direction.

The magnetic force F is given by

F = qvBsinθ

Where, q = charge magnitude, v = velocity of charge, B = strength of magnetic field. and θ =the angle between the directions of v and B.

Answer:

In classical mechanics, impulse (symbolized by J or Imp) is the integral of a force, F, over the time interval, t, for which it acts. Since force is a vector quantity, impulse is also a vector quantity. ... A resultant force causes acceleration and a change in the velocity of the body for as long as it acts.

Two objects are held close together. When they are released, they move toward one another. The conclusion is supported by this evidence is  the objects have opposite charges.

An electric charge is a physical property that causes matter to experience a force when in close proximity to other electrically charged matter. There are two types of electric charges: positive and negative. Protons, which are positively charged, and electrons, which are negatively charged, are subatomic particles that make up matter.

In general, the protons and neutrons in the nucleus of an atom have a net positive charge, while electrons, which orbit the nucleus, have a net negative charge. The charges of these subatomic particles are indicated by the symbols "p" for proton, "n" for neutron, and "e" for electron.

Know more about  electric charge   here:

https://brainly.com/question/23212561

#SPJ11

The powder takes the shape of a magnetic field.

Powder morphology is connected to the shape and size of powder particles and is strongly dependent on the manufacturing methods. For example, mechanical alloying/mechanical milling leads to unevenly shaped powder particles, while gas dissipation leads to spherically shaped particles.

Atomized metal powder particles come in two basic particle shapes: those that are almost superbly round called spherical, and those that have lopsided, rounded shapes, called spheroidal.

So we can conclude that Powders are a group of particles of different sizes.

Learn more about powder here: brainly.com/question/20628766

#SPJ1

Answer:

Explanation:

Let acceleration of fall be a .

v² = u² + 2as

v = 3.8 m /s

u = 0

s = 3.5 m

3.8² = 0 + 2 x a x 3.5

a = 2.06 m /s²

Since this acceleration is less than g , an upward force is acting on the firefighter in the form of friction . Let this force be F . Let mass of the firefighter be m .

m = 765 / 9.8

= 78.06 kg

mg - F = ma

765 - F = 78.06 x 2.06

765 - F = 160.8

F = 604.2 N .

Answer:

Different colour lights (RBG) uses additive properties to bring light of a certain color to our eyes.

Explanation:

:))

Hooke's law of elasticity is a principle in physics that states that the force required to extend or compress a spring by some distance is proportional to that distance. It is named after the English physicist Robert Hooke, who first stated the law in 1678. Hooke's law is often written as F = -kx, where F is the force applied to the spring, x is the distance it is stretched or compressed, and k is the spring constant, a measure of the stiffness of the spring.

Answer:

12.5 Ns.

Explanation:

From the question given above, the following data were obtained:

Force (F) = 250 N.

Time (t) = 0.05 s

Impulse =?

Impulse can be obtained by using the following formula:

Impulse = force × time

Impulse = 250 × 0.05

Impulse = 12.5 Ns

Thus, the Impulse applied to the ball is 12.5 Ns.

When a typical comet in the Oort cloud is only 1 km in diameter, then the mass of the Oort cloud is changes to  4.18×10⁹ kg.

The mass of each comet int he Oort cloud is,

mass = density × Volume

volume of sphere = 4/3(π×r²) where, r = radius of the sphere

From the given,

diameter = 1 km

radius = Diameter / 2 = 1/2(D)

Volume of the comet = 4/3 (π×r²) = 4/3 (π× (1/2 (10)³)²)

                                   = 4/3×(π) ×(1/8×10⁶)

Mass = density  × volume, where density = 1000 kg/m³

         = 1000  × 4/3×(π) ×(1/8×10⁶)

        = 4.18 ×10⁹ kg

When the typical comet in the Oort cloud is only 12 km in diameter the mass of Oort cloud is 4.18×10⁹ kg.

To know more about the Oort cloud :

https://brainly.com/question/23368033

#SPJ1

Ways Anthropologists are adjusting by focusing on the ways that migration and communication patterns connect groups and by altering their study methodologies.

The anthropologist's job description:

Anthropologists as well as archaeologists both research the origin, progress, and behaviors of individuals. They examine global linguistic and cultural diversity, physical characteristics, and artifacts found in archaeology. creating research plans that include underrepresented topics. using research methods that make advantage of an extensive study design. promoting the use of collaborative techniques to co-create material

What do anthropologists study?

Anthropology compares human communities across borders and through time. For instance, we contrast the current and earlier legal and religious systems. While contrasting political systems, including family relationships, we look at multinational organizations.

To know more about anthropologists visit:

brainly.com/question/17595144

#SPJ4

The centripetal force in Newtons provided by the friction between the blade of the skate and the ice is 490 N

The following data were obtained from the question:

The centripetal force can be obtained as illustrated below:

F = mv²/r

= (50 × 7²) / 5

= (50 × 49) / 5

= 2450 / 5

= 490 N

Thus, we can concluded that the centripetal force is 490 N

Learn more about centripetal force:

https://brainly.com/question/14021112

#SPJ1

The average acceleration of the motorcycle over the given distance is approximately 9.39 m/s².

To calculate the average acceleration of the motorcycle, we can use the formula:

Average acceleration = (final velocity - initial velocity) / time

First, let's convert the final velocity from km/h to m/s since the distance is given in meters. We know that 1 km/h is equal to 0.2778 m/s.

Converting the final velocity:

Final velocity = 78 km/h * 0.2778 m/s = 21.67 m/s

Since the motorcycle starts from rest (initial velocity is zero), the formula becomes:

Average acceleration = (21.67 m/s - 0 m/s) / time

To find the time taken to reach this velocity, we need to use the formula for average speed:

Average speed = total distance/time

Rearranging the formula:

time = total distance / average speed

Plugging in the values:

time = 50 m / 21.67 m/s ≈ 2.31 seconds

Now we can calculate the average acceleration:

Average acceleration = (21.67 m/s - 0 m/s) / 2.31 s ≈ 9.39 m/s²

To learn more about acceleration

https://brainly.com/question/2303856

#SPJ8

Answer:

Specific heat (Cp) water (at 15°C/60°F): 4.187 kJ/kgK = 1.001 Btu(IT)/(lbm °F) or kcal/(kg K)

The density of the oil when the water and oil are mixed is 661kg/m³.

From the information illustrated, water and then oil are poured into a U-shaped tube, open at both ends and they then come to equilibrium.

It was stated that suppose that H = 25.7 cm and h = 8.72 cm. It should be noted that the pressure ends at the one of the opening is the atmospheric pressure, therefore the gauge pressure will be:

∆P = pgh

This will be illustrated as:

(0.257)P = (1000) × (0.257 - 0.0872)

0.257P = 169.8

Divide

P = 169.8 / 0.257

P = 661kg/m³

The density is 661kg/m³.

Learn more about density on:

brainly.com/question/1354972

#SPJ1

Heat is the total energy of the motion of the molecules of a substance, whereas temperature refers to the measure of the average energy of the motions of the molecules in the substance. The heat is dependent on factors like the speed of the particles, the size of the particles and the number of particles, etc.

Differences between Heat and Temperature are :

Convert -40.3 degrees Celcius to Kelvin State.

The formula for Celsius to Kelvin temperature conversion is :

K = C + 273.15

Hence, -40.3 degrees Celcius to Kelvin is K = -40.3 + 273.15 = 232.85 K.

Find distance she traveled:

100m -25m = 75m

58 seconds / 2 second intervals = 29

29 x 2.6m = 75.4 meters total.

if the distance wasn’t rounded the statement was False.

Answer: False

The energy of a wave is proportional to its amplitude, according to the formula below:

Where A is the amplitude of the wave.

Looking at the image, the wave with the greatest amplitude is the green one.

Therefore the correct option is C.

Explanation:

Given:

Diameter = 200 m

Radius, r = 200/2 = 100 m

Time taken, t = 30 seconds

Formula to be used:

Distance traveled, = circumference of circle = 2πr

Answer:

Putting all the values, we get

Distance traveled = 2πr

So, the distance traveled by Raju is 628.57 m.

Now, magnitude of the displacement,

At the end of 30 seconds, Raju will come to starting position or initial position, so displacement is zero.

Answer:

20

Explanation:

Differentiate the above equation to get Acceleration.

Acceleration is the first derivative of velocity

so we get y' = 4t

substitute t = 5, we get acceleration = 20ms-2