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3 years ago

What is the difference between a physical change and a chemical change

2 answers:

6 0

A physical change in something doesn't change what the it is. For example, if you break glass, it will still be glass. In a chemical change where there is a chemical reaction, a new thing is formed and energy is either given off or absorbed. For example, when you burn a log. The carbon in the log is reacting to the oxygen to create ashe and smoke

Aleks [24]3 years ago

4 0

physical rearranges molecules but doesn't affect their internal structures while chemical <span>is any change that results in the formation of new chemical substances</span>

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How do you give an example for finding net force?

Crazy boy [7]

-- 6 people all trying to push a car out of snow

-- a Tug-o-War with 30 people of different sizes pulling on each end of the rope

-- you and your sister both pulling on the same doll (or Transformer)

-- lifting a book up from the table to a high shelf
taking a book down from a high shelf to the table
(one force is you; another force is gravity)

-- grabbing your big dog by his collar and trying to bring him inside

-- three people at the table all grab the ketchup bottle at the same time

7 0

3 years ago

Two identical satellites orbit the earth in stable orbits. One satellite orbits with a speed v at a distance r from the center o

jolli1 [7]

Answer:

c)At a distance greater than r

Explanation:

For a satellite in orbit around the Earth, the gravitational force provides the centripetal force that keeps the satellite in motion:

$G\frac{Mm}{r^2}=m\frac{v^2}{r}$

where

G is the gravitational constant

M is the Earth's mass

m is the satellite's mass

r is the distance between the satellite and the Earth's centre

v is the speed of the satellite

Re-arranging the equation, we write

$r = \frac{GM}{v^2}$

so we see from the equation that when the speed is higher, the distance from the Earth's centre is smaller, and when the speed is lower, the distance from the Earth's centre is larger.

Here, the second satellite orbit the Earth at a speed less than v: this means that its orbit will have a larger radius than the first satellite, so the correct answer is

c)At a distance greater than r

7 0

3 years ago

Martina has a sample of an unknown substance. She measures the substance. It’s mass is 13.5 grams, and it’s volume is 5 cm3 .Whi

Dominik [7]

Cm^3 is same as mL

13.5 g / 5 mL = 2.7 g/mL
look up densities of metals
aluminum has a density of 2.7 g/mL

6 0

3 years ago

All matter in the Universe consists of many substances called elements. <br><br> true or faluse

Mrrafil [7]

The answer to this statement is true!

8 0

3 years ago

Read 2 more answers

Some machines do not multiply the force that is applied to them

Katyanochek1 [597]

Answer:

Machine Efficiency

Explanation:

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work). The output work is always less than the input work because some of the input work is used to overcome friction. Therefore, efficiency is always less than 100 percent

5 0

2 years ago