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3 years ago

Please help me feel in the blanks Giving 30 points

Physics

1 answer:

maw [93]3 years ago

7 0

4:chemical properties can only be observed when a substance changes into another substance.

5: physical properties such as color and shape are easy to observe

6: in a chemical change an altered substance forms

7: cooking or baking food will result in a chemical change

8: a melting ice cube is a physical change

9: the rusting of iron is a chemical change

10: water boiling is a scientific physical change

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If a body having mass 40kg started moving initially with rest and it takes a velocity of 20m/sec in time 4 seconds. Find the val

baherus [9]

${\mathfrak{\underline{\purple{\:\:\: Given:-\:\:\:}}}} \\ \\$

$\:\:\:\:\bullet\:\:\:\sf{Mass \ of \ the \ body \ (m) = 40 \ kg}$

$\:\:\:\:\bullet\:\:\:\sf{Final \ velocity \ of \ the \ body \ (v) = 20 \ m/s}$

$\:\:\:\:\bullet\:\:\:\sf{Initial \ velocity \ of \ the \ body \ (u) = 0}$

$\\$

${\mathfrak{\underline{\purple{\:\:\:To \:Find:-\:\:\:}}}} \\ \\$

$\:\:\:\:\bullet\:\:\:\sf{Force \ exerted \ by \ the \ body \ ( F)}$

$\\$

${\mathfrak{\underline{\purple{\:\:\: Solution:-\:\:\:}}}} \\ \\$

☯ Using 1st equation of motion

$\\$

$\dashrightarrow\:\: \sf{v = u + at}$

$\\$

$\dashrightarrow\:\: \sf{20 = 0 + a(4)}$

$\\$

$\dashrightarrow\:\: \sf{20 = 4a}$

$\\$

$\dashrightarrow\:\: \sf{\dfrac{\cancel{20}}{\cancel{4}} = a}$

$\\$

$\dashrightarrow\:\: \sf{a = 5}$

$\\$

☯ Now, Finding the force exerted

$\\$

$\dashrightarrow\:\: \sf{F = ma}$

$\\$

$\dashrightarrow\:\: \sf{F = 40 \times 5}$

$\\$

$\dashrightarrow\:\: \sf{F = 200 \ N}$

$\\$

☯ Hence, $\\$

$\:\:\:\:\star\:\:\:\sf{The \ force \ exerted \ by \ the \ body \ is \ 200N}$

8 0

3 years ago

An automobile of mass 2000 kg moving at 30 m/s is braked suddenly with a constant braking force of 10000 N. How far does the car

saveliy_v [14]

Answer:

The car traveled the distance before stopping is 90 m.

Explanation:

Given that,

Mass of automobile = 2000 kg

speed = 30 m/s

Braking force = 10000 N

For, The acceleration is

Using newton's formula

$F = ma$

Where, f = force

m= mass

a = acceleration

Put the value of F and m into the formula

$-10000 =2000\times a$

Negative sing shows the braking force.

It shows the direction of force is opposite of the motion.

$a = -\dfrac{10000}{2000}$

$a=-5\ m/s^2$

For the distance,

Using third equation of motion

$v^2-u^2=2as$

Where, v= final velocity

u = initial velocity

a = acceleration

s = stopping distance of car

Put the value in the equation

$0-30^2=2\times(-5)\times s$

$s = 90\ m$

Hence, The car traveled the distance before stopping is 90 m.

6 0

3 years ago

4 what is the difference between an array's size declarator and a subscript?

Ber [7]

What is the difference between asize declarator and a subscript? The size declarator is ... When writing a function that accepts a two-dimensional array as an argument, which size declarator must you provide in the parameter for thearray? The second size ...

7 0

3 years ago

23) A high school website directs parents to not allow student access to blue laser pointers or allow the students to bring them

vekshin1

Mainly because of the higher energy of blue light than red light.

In fact, light is made of photons, each one carrying an energy equal to
$E=hf$
where h is the Planck constant while f is the frequency of the light.
The frequency of red light is approximately 450 THz, while the frequency of blue light is about 650 Hz. Higher frequency means higher energy, so blue light is more energetic than red light and therefore it can cause more damages than red light.

6 0

3 years ago

discuss the difference between molarity and molality, state the units of each, state the symbol of each, and give an example of

Afina-wow [57]

Molarity and molality both describe the concentration of a substance in terms of moles.
Molarity describes the number of moles of a substance per unit of volume, typically per liter (mol/l).
Molality describes the number of moles per unit of mass, typically kilograms (mol/kg).
When determining the molality of a solution, mol/kg can be obtained by finding the number of moles in the substance, and dividing that number by the the total weight in kilograms of that substance.
When determining the molarity of a solution, mol/l can be obtained by dividing the number of moles in a substance by the total volume in liters of that substance.

5 0

3 years ago