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3 years ago

Which statements describe chemical changes? Check all that apply.

Physics

2 answers:

hichkok12 [17]3 years ago

4 0

The answers are a,b, and d

larisa86 [58]3 years ago

3 0

The answers are a,b and d

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What would happen if an electron was added to an atom

amm1812

Answer:

If an electron is added to an atom energy is given off because of the negative energy.

Explanation:

5 0

3 years ago

A cat rolls up a hill. It’s initial Velocity is 10 m/s.n It’s final velocity is 0 m/s. The time was five seconds. Calculate Acce

aleksklad [387]

Answer:

$\boxed {\boxed {\sf a= -2 \ m/s^2}}$

Explanation:

Acceleration can be found by dividing the change in velocity by the time.

$a=\frac{v_f-v_i}{t}$

The final velocity of the cat was 0 meters per second and the initial velocity was 10 meters per second. The time was 5 seconds.

$v_f=0 \ m/s\\v_i=10 \ m/s\\t= 5 \ s$

Substitute the values into the formula.

$a=\frac{0 \ m/s-10 \ m/s}{5 \ s}$

Solve the numerator.

0 m/s-10 m/s= -10 m/s

$a=\frac{-10 \ m/s}{5 \ s}$

Divide.

$a= -2 \ m/s^2$

The acceleration of the cat was -2 m/s². The negative acceleration indicates slowing down or stopping.

6 0

3 years ago

Robert has just bought a new model rocket, and is trying to measure its flight characteristics. The rocket engine package claims

notka56 [123]

You must assume that the mass of the rocket and engine remains constant - even though the engine is burning.

You know the engine produces 13.8N for a distance of 14.6m

The total energy expended (work done) by the engine is FxD so you can calculate that

Now - some of that is given to the rocket as kinetic and potential energy, and some is expended against the drag force.

At the peak of its flight ALL the energy given to the rocket is potential energy (its velocity is zero) and that is calculated as mgh

So
Energy given to rocket = mgh
Energy expended by engine = F x D (D= height where engine stops)
Energy 'lost' to drag is the difference between the two values.

7 0

3 years ago

Read 2 more answers

On a cold day, snakes usually lie very still and eat little or nothing while birds usually move around and eat a lot of food. Wh

RoseWind [281]

Birds are warm-blooded, which means they need to move and eat more in the cold to stay warm; snakes are cold-blooded, so they don't have to.

5 0

4 years ago

A student in the front of a school bus tosses a ball to another student in the back of the bus while the bus is moving forward a

Veronika [31]

Answer:

Explanation:

good question. now the bus is moving in constant velocity . a student in front tosses a ball to the student in back. but we dont know the speed at which the student tosses a ball. we have to assume the speed

assume the speed of ball is slightly less than the speed of bus. in this case the stationary observer sees the ball in slower speed than the one inside the bus.

so a is correct

now assume the speed of ball is 1/2 the speed of bus. here stationary observer sees the ball the same speed as the one in bus observe

b is correct

assume the speed of ball is very small than the speed of bus . in this case the stationary observer see in grater speed than the student in bus

e also correct

so correct answer is d. it depends on the speed of ball tossed by the student in front.

6 0

4 years ago