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4 years ago

Melting, boiling, anf bending are physical changes but why is burning a chemical change

Physics

2 answers:

bija089 [108]4 years ago

7 0

Because burning is a non-reversible chemical change.

Nady [450]4 years ago

6 0

Burning is a chemical change because if it flames it could not back to the way it was it will be ash. Plus to start a fire with a lighter that has a chemical liquid that makes it flammable.

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Darryl throws a basketball at the gym floor. The ball bounces once on the floor and comes to rest in his coach’s hands. At which

mina [271]

Answer:

when the ball is at rest in his coach's hands.

Explanation:

The forces on the basketball are balanced when the basketball is not experiencing any acceleration. This happens when the ball is in his coach's hand: in fact, at that moment the ball is at rest, so it means that its acceleration is zero. According to Newton's second law, this also mean that the net force on the basketball is zero, so the forces on the ball are balanced:

$F=ma$

where F is the net force, m is the mass of the ball and a is the acceleration.

8 0

4 years ago

A force of 10N acts on a car for 3 seconds. The impulse imparted on the car is

ss7ja [257]

Answer:

30N*s

Explanation:

Given the following data;

Force = 10N

Time = 3 seconds

To find the impulse;

Impulse = force * time

Substituting into the equation, we have;

Impulse = 10 * 3

Impulse = 30Ns

7 0

3 years ago

A farmer using sustainable agriculrural practices will a. use increased crop diversity and fewer off the farm resources in order

kati45 [8]

a. use increased crop diversity and fewer off the farm resources in order to reduce pressure on resources

Explanation:

A farmer using sustainable agricultural practices will use increased crop diversity and fewer off the farm resources in order to reduce dependency on other resources.

The major goal of sustainable agriculture is to cultivate plants and groom livestock in the best way that won't alter the environment.

This usually entail the cultivation of different crops.
Diversity of crops provides the means to sustain and retain soil fertility naturally without having to add fertilizers.
In animal husbandry, some of wastes are used on farm and the excesses from the farm are used to feed livestock.
Sustainable agriculture is a practice of self-reliant agriculture without infringing on the environment.

learn more:

Human impact on rainforest brainly.com/question/12095428

#learnwithBrainly

6 0

3 years ago

An airplane engine starts from rest; and 2 seconds later, it is rotating with an angular speed of 300 rev/min. if the angular ac

elena-s [515]

First of all, we need to convert the angular speed from rev/min into rev/s:

$\omega_f=300 rev/min=5 rev/s$

The angular acceleration is the variation of angular speed divided by the time:

$\alpha=\frac{\omega_f-\omega_i}{t}=\frac{5 rev/s-0}{2 s}=2.5 rev/s^2$

And this is constant, so we can use the following equation to calculate the angle through which the engine has rotated:

$\theta(t)=\frac{1}{2}\alpha t^2 =\frac{1}{2}(2.5 rev/s^2)(2 s)^2=5 rev$

so, 5 revolutions.

3 0

3 years ago

A 50.0 N box sliding on a rough horizontal floor, and the only horizontal force acting on it is friction. You observe that at on

Vikki [24]

Answer:

-4.0 N

Explanation:

Since the force of friction is the only force acting on the box, according to Newton's second law its magnitude must be equal to the product between mass (m) and acceleration (a):

$F_f = ma$ (1)