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2 years ago

Why I’d it important to define a frame of reference?

Physics

1 answer:

Harman [31]2 years ago

3 0

Answer:

so two people can understand each other when presenting new ideas to each other

Explanation:

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Martha designed the model shown below to represent the positions of earth, sun, and moon during tides. the model most likely rep

Luda [366]

the model most likely represents the positions of earth, sun, and moon when there is: greatest difference between high and low tides
The high and low tides are created because of the combination of effects from the moon's gravitational forces with the sun's gravitational forces that affect the tide as the earth rotates

6 0

3 years ago

Suppose our experimenter repeats his experiment on a planet more massive than Earth, where the acceleration due to gravity is g

tekilochka [14]

Answer: a) It will take more time to return to the point from which it was released

Explanation: To determine how long it takes for the ball to return to the point of release and considering it is a free fall system, we can use the given formula:

$d=v_{0}.t + \frac{1}{2} .a.t^{2}$ , where:

d is the distance the ball go through;

v₀ is the initial velocity, which is this case is 0 because he releases the ball;

a is acceleration due to gravity;

t is the time necessary for the fall;

Suppose <em>h</em> is the height from where the ball was dropped.

On Earth:

h=0.t + $\frac{1}{2}.10.t^{2}$

h = 5t²

$t_{T}$ = $\sqrt{\frac{h}{5} }$

On the other planet:

h = 0.t + $\frac{1}{2}.30.t^{2}$

h = 15.t²

$t_{P}$ = $\sqrt{\frac{h}{15} }$

Comparing the 2 planets:

$\frac{t_{T} }{t_{P} } = \frac{\sqrt{\frac{h}{5} } }\sqrt{{\frac{h}{15} } }$

$\frac{t_{T} }{t_{P} }$ = $\sqrt{3}$ or $t_{T} = \sqrt{3}.t_{P}$

Comparing the two planets, on the massive planet, it will take more time to fall the height than on Earth. In consequence, it will take more time to return to the initial point, when it was released.

5 0

3 years ago

This triangle is an isosceles right triangle. This means that the triangle contains a _____ angle and _______ sides.

Svetlanka [38]

Answer:

There is a right angle and it has three sides.

Explanation:

There are two 45 degree angles and since a triangles sides ALWAYS add up to 180 we know the the other side has to be 90 degrees because 45+45+90=180. And we know that every triangle has three sides because "tri" means three.

3 0

2 years ago

Read 2 more answers

Calculate the work performed by an ideal Carnot engine as a cold brick warms from 150 K to the temperature of the environment, w

olga nikolaevna [1]

To solve this problem, apply the concepts related to the calculation of the work performed according to the temperature change (in an ideal Carnot cycle), for which you have to:

$W = \int\limit_{T_c}^{T_H} C (1-\frac{T_H}{T})$

Where,

C = Heat capacity of the Brick

$T_C$ = Cold Temperature

$T_H$ = Hot Temperature

Integrating,

$W = C (T_H-T_C)- T_H C ln (\frac{T_H}{T_C})$

Our values are given as

$T_H= 300K$

$T_C = 150K$

Replacing,

$W = (1) (300-150)-300(1)ln(2)$

$W = 150-300ln2$

$W = -57.94kJ \approx 58kJ$

Therefore the work perfomed by this ideal carnot engine is 58kJ

5 0

4 years ago

Which of the following has the lowest U value?

jarptica [38.1K]

Answer:

c. expanded polyurethane

Explanation:

Thermal performance of a building fabric is measured in terms of heat loss and is expressed as U-value or R-value. U-value is the rate of heat transferred through a structure divided by the difference in temperature across the structure with a unit of measurement of W/m²K.You can calculate the U-value of a by getting the reciprocal of the sum of thermal resistances , R, making the building material.

If you have the value of R, then U=1/R

Material size R U

plywood 1" 1.25 0.8

Poured concrete 2" 0.99 1.010

Expanded polyurethane 1" 6.5 0.1538

Asbestos shingles 1" 0.03 33.33

The material with lowest U-value is expanded polyurethane

4 0

3 years ago