pls help !!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer:

Melting point of a substance is the temperature at which a substance changes from a solid to a liquid. A change of state like melting is a physical change because it doesn’t alter the identity of the substance. In other words, melting point is a physical property because you can determine an object’s melting point without changing the substance. For example, when a substance like ice melts into water, the identity of the substance doesn’t change; the substance is water before and after the physical change. On the other hand, flammability is a chemical property because burning an object is a combustion reaction that leads to the creation of new substances. When you burn a piece of wood, it reacts with oxygen in the air to produce heat, light, carbon dioxide, and water vapor.

Explanation:

There are a lot of examples to choose from.

Answer:

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

force = mass × acceleration

From the question we have

force = 6500 × 0.3

We have the final answer as

Hope this helps you

Answer:  71.43 kilograms

This value is approximate rounded to two decimal places.

=====================================================

Explanation:

The ground is pushing up with a normal force of 700 N. Because the box is sitting still, this means the force of gravity is pulling the box down with a force of 700N to keep things balanced.

If the force of gravity was greater than 700N, then the box would fall through the ground. If the force of gravity was smaller than 700N, then the box would be accelerated upward. Since neither event is happening, the force of gravity must be equal to the normal force.

Now turn to Newton's second law which says

F = ma

where F is the force, m is the mass and 'a' is the acceleration. We're given the acceleration of gravity is roughly 9.80 m/s^2. So a = 9.80

The force we'll plug in is F = 700. The value of m is unknown, but we can solve for it as such

F = ma

700 = m*9.80

700 = 9.08m

9.80m = 700

m = 700/9.80

m = 71.4285714285714

m = 71.43

The mass is roughly 71.43 kilograms.

Answer:

the graph represents an endothermic reaction

Explanation:

remember:

endo- inside

exo- out

Answer:

Cohesion

Explanation:

Surface tension of water refers to the ability of the surface of water as a liquid to resist an external force. Surface tension of a liquid like water is dependent on the force of attraction that hold its molecules to one another, which is a force called COHESIVE FORCE.

Cohesion is a property of water characterized by the ability of water molecules to be attracted to one another. This cohesive property causes its molecules to be able to resist external forces or in other words is responsible for the SURFACE TENSION. Hence, the stronger the cohesive force between molecules of a liquid, the higher the surface tension.

Power quotient of : _____?

Answer :

[tex]p = \frac{w}{t} [/tex]

P is Power (Watt)

W is Work (Joule)

T is Time (second)

So, it means Work and Time is the quotient of Power. (B)

Answer:

I think it a

Explanation:

Answer:

c

Explanation:

Answer:

The minimum pressure car tire pressure is 300,000 Pa

Explanation:

Pressure

It's a measure of the force exerted by an object per unit surface:

[tex]\displaystyle P=\frac{F}{A}[/tex]

Where F is the force applied on a surface area A.

We are given the total weight of a car with passengers as Ft=30,000 N and we also know the area of contact of each tire with the ground as [tex]A=0.025 m^2[/tex].

The minimum pressure each tire can have is when the total weight is evenly distributed in all four tires, thus F=Ft/4=7,500 N.

Calculating the pressure:

[tex]\displaystyle P=\frac{7,500}{0.025}[/tex]

P=300,000 Pa

The minimum pressure car tire pressure is 300,000 Pa

Answer:

Photosynthesis is the process of using water, carbon dioxide and sunlight to produce sugar. The process of photosynthesis requires specialized cellular structures called chloroplasts to capture energy from the Sun and converted into chemical energy.

Explanation:

Answer:

The time it takes for the jet to reach landing speed is approximately 0.136 hours which is approximately 489 seconds

The landing speed is approximately 466.365 km/hr

Explanation:

The given parameters are;

The initial cruising speed of the jet = Mach 0.79 = 844 km/hr

The rate of speed reduction in the last 89 km = -2780 km/hr²

The distance it  takes the jet to reduce its speed for landing = 89 km

Given the above information,  we make use of the following equation of motion;

s = u·t - 1/2·a·t²

v² = u² - 2·a·s

Where;

s = The distance over which the acceleration (deceleration) is applied = 89 km

u = The initial velocity = 844 km/hr

t = The time taken for the accelerating/decelerating motion

v = The final velocity (landing speed)

Substituting the values gives;

v² = 844² - 2·(2780)·89 = 217496

v = √217496 = 466.365 km/hr

v ≈ 466.365 km/hr

Therefore, the landing speed, v  ≈ 466.365 km/hr

The time it takes is given by the equation, v = u - a·t

Therefore;

t = (u - v)/a = (844 - 466.365)/2780 ≈ 0.136 hours

The time it takes for the jet to reach landing speed ≈ 0.136 hours

From, s = u·t - 1/2·a·t², we have

89 = 844·t - 1/2 × 2780 × t²

89 = 844·t - 1390 × t²

1390 × t² - 844·t + 89 = 0

Solving with an online application gives;

t = 211/695 + (√(27187/2))/695 = 0.4715 hours or t = 211/695 - (√(27187/2))/695 = 0.136 hours

We note that the second time is for the time it will take the jet to get back to 89 km after reaching a speed of 0

Therefore, the correct time is t = 0.136 hours

The time it takes for the jet to reach landing speed ≈ 0.136 hours

Answer:

2.46

Explanation:

From the question given above, the following data were obtained:

Critical angle (C) = 24 °

Refractive index (n) =?

The refractive index of the diamond can be obtained by using the following formula as illustrated below:

Refractive index (n) = 1 / sine [critical angle (C)]

n = 1/sine C

n = 1 / sine 24 °

n = 1/0.4067

n = 2.46

Thus, the refractive index of the diamond is 2.46

Answer:

True

Explanation:

normal force=mass*gravitational force

normal force=40*0

normal force=40

Answer:

you can use a balance

Explanation:

when you tend to measure something you are using your brain so why dont you use your brain dimwitt

Kinematics

First Velocity (Vf) = 18 m/s

Last Velocity (Vl) = 19 m/s

time (t) = 5 seconds

acceleration = ______?

Answer :

Vl = Vf + a × t

19 = 18 + a × 5

19 - 18 = 5a

1 = 5a

1 / 5 = a

0,2 m/s² = a ✅

Answer: 0.2 m/s^2 east

Explanation:

A PE X

simple methods to carry a sufferer encompass the four-hand seat, backpack carry, ski pole or tree limb backpack carry, and coiled rope seat. In the first method, two rescuers interlock hands. Each rescuer first grasps his right wrist with his left hand.

Answer:

The average speed of an object is defined as the distance traveled divided by the time elapsed. Velocity is a vector quantity, and average velocity can be defined as the displacement divided by the time.

Answer:

once a week

Explanation:

once a week so answer B

Answer:

B-Once a week

Explanation:

You answer is B-Once a week

Answer:

thats a lot, which one u want me to do?

Explanation:

Answer:

0.26

Explanation:

Given that :

Diameter of ball = 3.81 cm = 3.81/100 = 0.0381 m

Radius (r) = 0.0381 / 2 = 0.01905 m

Average density of ball (Db) = 0.0842 g/cm³ = (0.0842 / 1000)kg / 10^-6 = 0.0842/ 1000 * 10^6 = 84.2kg/m³

Density of water (Dw) = 1000kg/m³

Volume of hollow ball: (4/3) * pi * r³

V = (4/3) * π * 0.01905^3

V = 0.0000289583 m³

Required force = (Dw * V * g) - (Db * V * g)

= (1000 * 0.0000289583 * 9.8) - (84.2 * 0.0000289583 * 9.8)

= 0.259896109172

= 0.2598 N

To determine the force that must be applied to the hollow ball to hold it stationary while it is completely submerged under water is 0.2243 Newton.

Given the following data:

Density of water = 1000 [tex]kg/m^3[/tex]

Conversion:

Diameter of hollow ball = 3.81 centimeters to meters = [tex]\frac{3.81}{100} = 0.0381\;m[/tex]

Density of hollow ball = 0.0842 [tex]g/cm^3[/tex] to [tex]kg/m^3[/tex] = [tex]\frac{0.0842 \times 10^6}{1000} = 84.2 \;kg/m^3[/tex]

To determine the force that must be applied to the hollow ball to hold it stationary while it is completely submerged under water:

First of all, we would calculate the volume of the hollow ball by using the formula:

[tex]Volume = \frac{4}{3} \pi r^3\\\\Volume = \frac{4}{3} \times 3.142 \times 0.01905^3\\\\Volume = 4.19 \times 0.0000069\\\\Volume = 0.000029 \;m^3[/tex]

Next, we would find the force required for water and the hollow ball:

For water:

[tex]F_w = D_wVg\\\\F_w = 1000 \times 0.000029 \times 9.8\\\\F_w = 0.2842\; Newton[/tex]

For hollow ball:

[tex]F_h = D_hVg\\\\F_h = 84.2 \times 0.000029 \times 9.8\\\\F_h = 0.0239\; Newton[/tex]

Now, we can find the force that must be applied to the hollow ball:

[tex]Force = F_w - F_h\\\\Force = 0.2482 - 0.0239[/tex]

Force = 0.2243 Newton

Read more: https://brainly.com/question/18320053

Answer:

The correct answer is B

Answer:

D

Explanation:

because all are reffering to the answer you need

Answer: KE = 25 J

Explanation: You must use the formula

KE = 1/2 m v²

to solve this problem.

KE = 1/2 (10 Kg) (5 m/s)

KE = 1/2 (50 kgm/s)

KE = 25 J

Answer:

[tex]V=0.56~m^3[/tex]

Explanation:

Density

It's a measure of the mass of an object or substance per unit volume. It can be calculated as:

[tex]\displaystyle D=\frac{M}{V}[/tex]

Given the density of solid copper as [tex]D=8960~Kg/m^3[/tex], we will calculate the volume occupied by M=5000 Kg of copper solving the above equation for V:

[tex]\displaystyle V=\frac{M}{D}[/tex]

Substituting:

[tex]\displaystyle V=\frac{5000}{8960}[/tex]

Calculating:

[tex]V=0.558~m^3[/tex]

Expressed to two significant figures:

[tex]V=0.56~m^3[/tex]

Answer:

The atomic mass of an atom that has 5 protons and 7 neutrons would be 12.

Explanation:

In all cases, the number of protons added to the number of neutrons equate to the mass of an atom. Electrons do have mass, but it's so miniscule and insignificant that it doesn't contribute to the overall mass of the atom, so there's no need to count them.  

Bonus Information:

DO NOT CONFUSE MASS WITH CHARGE! Protons and neutrons are the only particles that contribute to the mass of an atom. Meanwhile, protons (+) and electrons (-) are the only particles that have a charge. As it says in its name, neutrons are neutral or have no charge.

Remember:

C = p - e

M = p + n

C = atomic charge, M = atomic mass, p =protons, n = neutrons, e = electrons

I hope this helps!

Answer:

0.03s

Explanation:

Period of wave and its frequency are closely related. Period is the inverse of frequency.

The period of a wave is the time taken for a number of waves to pass through a particular point.

The frequency of a wave is the number of waves that passes through a point at a particular time.

So;

          f  = [tex]\frac{1}{T}[/tex]  

f is the frequency

T is the period

   Period of the wave  = [tex]\frac{1}{30}[/tex]   = 0.03s

Answer:

a

Explanation:

Answer:

Heavy objects fall at the same rate (or speed) as light ones. The acceleration due to gravity is about 10 m/s2 everywhere around earth, so all objects experience the same acceleration when they fall.

Explanation:

Answer:

Speed = 0.5 m/s

Explanation:

Time = 3min = 180 seconds

Distance = 90 meters

[tex]Speed =\frac{Distance}{Time} \\\\Speed= \frac{90}{180} \\\\Speed = \frac{1}{2} \\\\Speed =0.5\:m/s[/tex]

Answer:ttttrsc

Explanation:eeeeee