What is the unit for efficiency?
What is the biggest number the
efficiency can be?
How do you work out the % efficiency?

Speed has no direction.

Velocity has one.

Answer:

True

Explanation:

The girl's reference frame must be moving with the same speed as the plane.

If an observer is stationary and he watches a car moving he can observe that the car has a momentum and is moving with certain speed. But if the observer is in the car or moving with same speed, the car does not appear to move away form the observer. Likewise, two observers moving with different speed will have different observation about the same car.

Similarly, if the girl describes the plane is not moving that means either she is in the plane or moving with the same speed along with the plane.

Learn more about frame of reference:

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Answer:

I think its A

Explanation:

if its every 3 seconds wouldnt it be 3.0 Hz

Answer:

(b) 490 N downwards

Explanation:

(b) Formula : w= mg

m is the mass of the object

g is a gravitational constant (9.8)

w= mg

= 50×9.8

= 490 N downwards

Answer:

[tex]\dfrac{-1}{2}[/tex]

Explanation:

We need to divide the second number by the first number and the numbers are 3/4,-3/8​.

First number = 3/4

Second number = -3/8

Dividing the second number by the first number.

So,

[tex]\dfrac{\dfrac{-3}{8}}{\dfrac{3}{4}}[/tex]

We know that,

[tex]\dfrac{\dfrac{a}{b}}{\dfrac{c}{d}}=\dfrac{a}{b}\times \dfrac{d}{c}[/tex]

So,

[tex]\dfrac{\dfrac{-3}{8}}{\dfrac{3}{4}}=\dfrac{-3}{8}\times \dfrac{4}{3}\\\\=\dfrac{-1}{2}[/tex]

So, the answer is (-1/2)

Answer:

6km/hr

Explanation:

3km = 30mins

x(km) = 1hr

1hr = 60 x 60 = 3600secs

30min = 30 x 60 = 1800secs

3 x 3,600/x X 1,800

x = 10,800/1,800

x = 6km/hr

To solve the problem we must know about speed, distance, and time.

We know that speed, distance, and time all are in a relationship with each other. this relationship can be given as,

[tex]\rm{Speed = \dfrac{Distance}{Time}[/tex]

Given to us

A student walks 3 km in 30 minutes.

We know distance can be written as the product of speed and time, therefore,

[tex]\rm Distance = \rm speed \times \rm Time[/tex]

Substituting the values we get,

[tex]\rm 3\ km = Speed \times 0.5\ hour[/tex]

[tex]\rm speed = \dfrac{3\ km}{0.5\ hour}[/tex]

speed = 15 km\h

Hence, the speed of the student is 15 km\hour.

Learn more about speed, distance, and time:

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Answer:

Wind

Explanation:

I had this question on one of my tests, and I got it right

Answer:

Cheers

Answer:

hmmmmm

Explanation:

I am gonna say D.

if I am right plz give me a brainliest

Answer:

Mechanical

Explanation:

The tank is at rest. And energy of any substance at rest is known as potential energy.

Now, in forms of energy, potential energy is a type of mechanical energy.

Thus, the correct option is mechanical Energy.

Answer:

An ax being used to hit wood (action) and the wood splitting after being hit

by the ax (reaction)

Explanation:

Answer:

d

Explanation:

Answer:

0 J is left (No amount of the original 35000 J energy is left)

Explanation:

From the question

Kinetic Energy (K.E) = 1/2mv²................... Equation 1

Where m = mass of the car, v = velocity of the car.

make m the subject of the equation.

m = 2K.E/v²..................... Equation 2

Given: K.E = 35000 Joules, v = 120 km/h = (120×3600/1000) = 432 m/s

Substitute these values into equation 2

m  = (2×35000)/432²

m = 0.375 kg.

If a brake is suddenly apply,

Then, the velocity of the car = 0 m/s.

Therefore,

K.E = 1/2(0.375×0²)

K.E = 0 J.

From the baove analysis, No amount of the original 35000 J energy is left.

Answer:

The length traveled by an object moving in any direction or even changing direction is called distance. The location of an object in a frame of reference is called position. For straight line motion, positions can be shown using a number line. The separation between original and final position is called displacement

Explanation:

good luck

Answer:

I'm pretty sure its product.

Explanation:

Hope this helps and have a wonderful day!!!!

Answer:

125 J

Explanation:

Work done = force * distance

work = 25 * 5

work = 125 J

Answer:

Thx!

Explanation:

Answer:

G. it enables people to use pots and pans made of metal to cook food

Explanation:

Metals are known to be substances with a relative high melting point, which means that it takes a very high temperature to melt them. As used in this question, copper (Cu) and iron (Fe) at metallic elements that have high melting points.

One advantage of this property based on the options provided is that "it enables people to use pots and pans made of metal to cook food". This is because cooking food requires subjecting them to a constant temperature from a heat source e.g cooker or stove.

The material used to hold the food being cooked must possess a very high melting point to withstand the heat, hence, the importance of these metallic substances. Most pots and pans are made of steel, an alloy of iron, hence, they have high melting point.

Answer:

an example for applied force is

Explanation:

The applied force is the force applied to the object to either displace it or change its shape.

HOPE THIS HELPS