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Harlamova29_29 [7]

3 years ago

11

Hi can someone PLEASE HELP ME. I asked this question 3 times already and haven't gotten an answer. I give brainliest to whoever

answers first. I have about 13 minutes. PLEASE HELP!!!!!!

2 answers:

Serggg [28]3 years ago

7 0

HCl + NaOH -> H2O + NaCl

CaCO3 + KI -> K2CO2 + CaI2

AlF3 + Mg(NO3)2 -> Al(NO3)3 + MgF2

lina2011 [118]3 years ago

6 0

Did you get the answer to it?

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Your car is initially at rest when you hit that gas and the car begins to accelerate. The forward force of the car is 5630 N whi

Neporo4naja [7]

330...................

6 0

3 years ago

90 kgkg ice skater moving at 10.0 m/sm/s on the ice encounters a region of roughed up ice with a coefficient of kinetic friction

pychu [463]

Answer:

12.43m

Explanation:

information we know:

mass:

$m=90kg$

initial velocity:

$v_{i}=10m/s$

coefficient of kinetic friction:

$\mu=0.41$

with this information we use Newton's second law:

$F=ma$

where $F$ is the force acting on the person, and $a$ is its acceleration.

analyzing the forces acting the vertical axis y:

$N-mg=ma$

where N is the normal force and -mg is the weight of the person (weight and normal force are the only two forces acting on the vertical axis)

since the person is not moving up or down there is no acceleration in the y axis (a=0):

$N-mg=0\\N=mg$

and now analyzing the forces acting on the horizontal axis x (using Newton's second law):

$F=ma$

the only horizontal force on the person is the fricction, so:

$-F_{fr}=ma$

where $-F_{fr}$ is the force due to friction (negative because it opposes the movement) and it is defined as:

$F_{fr}=\mu N$

and since we know that N=mg:

$F_{fr}=\mu mg$

thus the second law for the horizontal movement is:

$-\mu mg=ma\\-\mu g=a$

substituting $\mu=0.41$ and $g=9.81m/s^2$

$a=-(0.41)(9.81m/s^2)\\a=-4.0221m/s^2$

and then we use the following kinematic equation :

$v_{f}^2=v_{i}^2+2ax$

to find the displacement x of the ice skater, since the final velocity is equal to zero (vf=0 , because the ice skaters stops), we get

$0=v_{i}^2+2ax\\v_{i}^2=-2ax\\\frac{v_{i}^2}{-2a}=x$

and we substitute the known values:

$\frac{(10m/s)^2}{-2(-4.0221m/s^2)}=x\\ 12.43m=x$

the answer is 12.43m

3 0

4 years ago

An atomic mass unit is equal to

elixir [45]

One-twelfth the mass of carbon-12 atom

6 0

3 years ago

Read 2 more answers

A spring has a natural length of 14 cm. If a 23-N force is required to keep it stretched to a length of 20 cm, how much work W i

lubasha [3.4K]

Answer:

1.78 J

Explanation:

Find the spring coefficient using Hooke's law:

F = k Δx

23 N = k (0.20 m − 0.14 m)

k = 383.33 N/m

The work is the change in energy:

W = PE₂ − PE₁

W = ½ kx₂² − ½ kx₁²

W = ½ k (x₂² − x₁²)

W = ½ (383.33 N/m) ((0.17 m)² − (0.14 m)²)

W = 1.78 J

4 0

3 years ago

What does a branching tree diagram show? The evolution in the size of organisms The order in which specific traits may have evol

Anarel [89]

Answer:

a) Species change over time; some traits become more common, others less. This process of change is driven by natural selection. The traits that become more common are the ones that are “adaptive” or “increase fitness” (that is, a creature's chances of living longer and producing more offspring)

Explanation:

because it is

8 0

4 years ago