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3 years ago

11

Which of the following is a physical change

1 answer:

topjm [15]3 years ago

6 0

Answer: A physical change can be a change in size, shape, or color.

Explanation:

One type of physical change is a phase change. Consider water for example, if liquid water evaporated into a vapor, a phase change occurred. A phase change is a type of physical change. The difference between a physical change and chemical change is that a physical change doesn't change the substance identity. A chemical change can however change the identity of the substance.

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Your shopping cart has a mass of 65 kilograms, In order to accelerate the shopping cart down an aisle at 0.3 m/sec2, what force

garri49 [273]

Remember Newton's second law: F=ma

to get the force in newtons, mass should be in kg and acceleration in m/s^2

conveniently, we don't need to convert units

we just need to multiply the two to get the force

65* 0.3 = 19.5 kg m/s^2 or N

if significant digit is an issue, the least number if sig figs is 1 so the answer would be 20 N

4 0

3 years ago

What are the uses of rockets

lora16 [44]

They are used to be able to go out of Earth and into space to Be able to explore and toBe able to prove and tell about Earth and space

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3 years ago

Sammy squirrel is steering his boat at a heading of 327 degree at 18mph. The current is flowing at 4mph at a heading of 60 degre

Tanya [424]

Answer:

59.97 º at 18.23 mph

Explanation:

To find Sammy's course you have to add the two velocities (vectors), 18 mph 327º and 4 mph 60º.

To add the two vectors analytically you decompose each vector into their vertical and horizontal components.

<u>1. 18 mph 327º</u>

Horizontal component: 18 mph × cos (327º) = 15.10 mph

Vertical component: 18 mph × sin (327º) = - 9.80 mph

Vector notation:

$15.10\hat i-9.80\hat j$

<u>2. 4 mph 60º</u>

Horizontal component: 4 mph × cos (60º) = 2.00 mph

Vertical component: 4 mph × sin (60º) = 3.46 mph

Vector notation:

$2.00\hat i+3.46\hat j$

<u>3. Addition:</u>

You add the corresponding components:

$15.10\hat i-9.80\hat j+2.00\hat i+3.46\hat j\\ \\ 17.10\hat i-6.34\hat j$

To find the magnitude use Pythagorean theorem:

$\sqrt{17.1^2+6.34^2}= 18.23$

<u>4. Direction:</u>

Use the tangent ratio:

$tan(\alpha )=opposite/adjacent=3.46/2.00=1.73$

Find the inverse:

arctan (1.73) ≈ 59.97º

5 0

3 years ago

An 80.0-kg object is falling and experiences a drag force due to air resistance. The magnitude of this drag force depends on its

Zinaida [17]

Answer:

Terminal velocity of object = 12.58 m/s

Explanation:

We know that the terminal velocity is attained when drag force and gravitational force are of the same magnitude.

Gravitational force = mg = 80 * 9.8 = 784 N

Drag force = $12.0v+4.00v^2$

Equating both, we have

$784=12.0v+4.00v^2\\ \\ v^2+3v-196=0\\ \\ (v-12.58)(v+15.58)=0$

So v = 12.58 m/s or v = -15.58 m/s ( not possible)

So terminal velocity of object = 12.58 m/s

3 0

3 years ago

You could swallow a capsule of germanium, Ge (atomic number 32), without significant ill effects. If a proton were added to each

Ronch [10]

Answer: A

Explanation:

Germanium, is atomic number 32, and if you add a proton, Germanium converts to arsenic. arsenic is very poisonous.

4 0

3 years ago