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Answer:

Density is the mass of an object divided by its volume. ... Density often has units of grams per cubic centimeter ... Density is not something that is directly measured.

Explanation:

given

mass (m) = 315 g

length (l) = 7 cm

width (b) = 3 cm

height (h) = 5 cm

Now

volume (v) = l * b * h

V = 7 * 3 * 5

V = 105 cm³

Density (d) = ?

We know

density is defined as mass per unit volume so

d = m / v

d = 315 / 105

d = 3 g/cm³

Therefore density = 3 g/cm³

Note

If the question is asked to write in SI unit of density then u have to write the unit of density as kg/m³

Hope it will help :)

Answer:

when mass will increase then kinetic energy will also increase because both have positive relationship

Explanation:

when volume increase then molecule come closer then more movement will occurs and kinetic energy increase

Answer:

The answer are:

The wheel and axle is a simple machine that reduces the friction involved in moving an object, making the object easier to transport. ... Once the object is moving, the force of friction opposes the force exerted on the object. The wheel and axle makes this easier by reducing the friction involved in moving an object.

In addition to reducing friction, a wheel and axle can also serve as a force multiplier, according to Science Quest from Wiley. If a wheel is attached to an axle, and a force is used to turn the wheel, the rotational force, or torque, on the axle is much greater than the force applied to the rim of the wheel.

Answer:

Answer: B

"Ball 1 at 0.21 m/s left, Ball 2 at 0.22 m/s left"

Answer:

ball 4 has a positve charge

Explanation:

-Ball 2: is negative because it is repelled by ball one (like signs repel)

- ball 3: is also negative because it is repelled by ball one (like signs repel)

- Ball 4: is positive because it is attracted by ball 3 (opposite signes attract)

Answer:

A

Explanation:

Givens

d = 100 meters plus the depth of the well

d = 100 + x                          where x is the depth of the well.

vi = 0 m/s                           The object is dropped. It was not thrown.

t = 5 seconds

a = 9.81 m/s^2

formula

d = vi*t  +  1/2 a t^2

solution

100 + x = 0 + 1/2 * 9.81 * 5^2

100 + x = 122.625             Subtract 100 from both sides

x = 122.625 - 100

x = 22.6  m

The well is 22.6 meters deep.

Answer:

I think A= 5M/S is answer

Answer:

VR = [tex]\frac{Radius of wheel}{Radius of axle}[/tex]

Explanation:

A machine is a device that can be used to overcome a load by the application of an effort through a pivot. Examples are: pulleys, wedge, screw jack, wheel and axle etc.

The wheel and axle is a simple device that can be used to lift a load through a height. Its velocity ratio (VR) can be determined by:

VR = [tex]\frac{Radius of wheel}{Radius of axle}[/tex]

Note that for a practical wheel and axle, the radius of the wheel is greater than the radius of the axle.

Answer:

I believe you are correct but we just started this unit

Explanation:

Answer: Optical test is a test which is used to assess vision and ability of the person to focus on the objects.

Explanation:

The following are the advantages of utilizing plane mirror in optical testing:

1. When a plane mirror is used for testing the image of the test card must be placed at distance equal to the distance of the object.  

2. Larger distance in between the object or test card and viewer is obtained. This can help in determining the exact ability of the eye to focus on objects.

Answer:

4048 = 115x/100.

Explanation:

Profit P = (15/100) X x.

P= 15x/100.

15x/100 = 4048- x.

4048 = 15x/100 + x.

4048 = 115x/100.

Answer:

Acceleration, a = 0.65m/s² due North.

Explanation:

Given the following data;

Initial velocity = 12mi/hr

Final velocity = 25mi/hr

Time = 9 secs

To find the acceleration;

First of all, we would convert miles per hour to meters per seconds.

[tex] Initial \; velocity = \frac {12 * 1609.344}{60*60} = \frac {19312.128}{3600} = 5.37m/s [/tex]

[tex] Final \; velocity = \frac {25 * 1609.344}{60*60} = \frac {40233.6}{3600} = 11.18m/s [/tex]

Now to find the acceleration;

Mathematically, acceleration is given by the equation;

[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]

Substituting into the equation, we have;

[tex]a = \frac{11.18 - 5.37}{9}[/tex]

[tex]a = \frac{5.81}{9}[/tex]

Acceleration, a = 0.65m/s² due North.

The intensity of the electric current of a circuit is 123A and the electric charge is 1.7C to find the time interval in which the electric charge is transported.

Given that,

Current, I = 123 A

Electric charge, q = 1.7 C

To find,

The time interval in which the charge is transported.

Solution,

The electric current is given by electric charge per unit time. So,

[tex]I=\dfrac{q}{t}\\\\t=\dfrac{q}{I}\\\\t=\dfrac{1.7}{123}\\\\t=0.0138\ s[/tex]

So, the required time is 0.0138 seconds.

Answer:

For, heating purposes more the quantity of  water more will be the heating. Clearly, underground heating would have more water and hence, it will have edge over the  water heater system.

Moreover, for things at the same temperature, the thing with more molecules has more total kinetic energy (thermal energy) than the thing with fewer molecules. The groundwater heating system uses heat from the heat stored naturally in groundwater or aquifers. Thus, saving the cost of power required to heat in normal water heater.

Explanation:

The groundwater heating system will warm the school more than the water heater system due to the fact that it uses more water more than the other system.

Based on the complete question, it should be noted that the addition of energy leads to an increase in motion which results in the rise in temperature.

The groundwater heating system will warm the school more than the water heater system due to the fact that it uses more water more than the other system even though its water isn't as warm as in the other system.

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Answer:

[tex]6\:\mathrm{m/s}[/tex]

Explanation:

Denote average speed by [tex]S=\frac{d}{t}[/tex] where [tex]d[/tex] is total distance travelled and [tex]t[/tex] is time.

Plugging in given values, we get:

[tex]S=\frac{30}{5}=\fbox{$6\:\mathrm{m/s}$}[/tex].

Answer:

s

Explanation:

Answer:

Explanation:

The velocity can be found by using the formula

[tex]v = \sqrt{ \frac{2k}{m} } \\ [/tex]

k is the kinetic energy

m is the mass

From the question we have

[tex]v = \sqrt{ \frac{2 \times 4116}{4200} } \\ = 1.4[/tex]

We have the final answer as

Hope this helps you

Answer:

The speed of the lift is 1.4 m/s

Explanation:

Kinetic Energy

Is the type of energy of an object due to its motion. It's proportional to the square of the speed and the mass.

The equation for the kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

It's given the mass of the lift as m=4,200 kg and its kinetic energy K=4,116 J. To calculate the speed (magnitude of velocity), we solve the formula for v as follows:

[tex]\displaystyle v=\sqrt{\frac{2k}{m}}[/tex]

[tex]\displaystyle v=\sqrt{\frac{2*4,116}{4,200}}[/tex]

[tex]\displaystyle v=\sqrt{1.96}[/tex]

v = 1.4 m/s

The speed of the lift is 1.4 m/s

Answer:

1400 N

Explanation:

Verá, durante el salto mortal, el piloto se mueve en una trayectoria circular y la fuerza que actúa sobre él es una fuerza centrípeta.

Sea la fuerza centrípeta F, la masa del piloto (m) = 70 Kg, el radio (r) = 500 my la velocidad (v) = 360 km / hr * 1000/3600 = 100 m / s

F = mv ^ 2 / r

F = 70 * (100) ^ 2/500

F = 1400 N

Answer:

1m/s²

Explanation:

Given parameters:

Initial velocity  = 2m/s

Final velocity  = 4m/s

Time of chase  = 2s

Unknown:

Acceleration = ?

Solution:

Acceleration is the rate of change of velocity with time;

 A = [tex]\frac{v - u }{t}[/tex]  

A is the acceleration

v is the final velocity

u is the initial velocity

t is the time taken

      A  = [tex]\frac{4 - 2}{2}[/tex]   = 1m/s²

None can.

A clinical thermometer only measures temperatures above +30°C.

Mercury and alcohol are both frozen solid at -50°C.

Answer:

8 J and 2 J

Explanation:

Given that,

Mass of the rubber ball, m = 1 kg

Initial speed of the rubber ball, u = 4 m/s (in east)

Final speed of the rubber ball, v = -2 m/s (in west)

We need to find the kinetic energy of the ball before it hits the wall, the kinetic energy of the ball after it bounces off the wall.

Initial kinetic energy,

[tex]K_i=\dfrac{1}{2}mv^2\\\\K_i=\dfrac{1}{2}\times 1\times (4)^2\\\\K_i=8\ J[/tex]

Final kinetic energy,

[tex]K_f=\dfrac{1}{2}mv^2\\\\K_f=\dfrac{1}{2}\times 1\times (2)^2\\\\K_f=2\ J[/tex]

So, the initial kinetic energy is 8 J and the final kinetic energy is 2 J.

The kinetic energy of the ball after it bounces off the wall is 2.0 Joules.

The kinetic energy of an object is the energy that is in motion or performing work. It can be expressed by using the formula:

[tex]\mathbf{K.E = \dfrac{1}{2}mv^2}[/tex]

The Kinetic energy of the ball after the collision and when it bounces off the wall is computed as:

[tex]\mathbf{K.E = \dfrac{1}{2} \times 1 \times 2.0^2}[/tex]

K.E = 2.0 Joules

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Answer:

Ernest Rutherford, 1st Baron Rutherford of Nelson

Answer:

It's 4m/s

Explanation:

V = u _ at, at u = 44m/s

44 + [-4]10

4m/s

Answer:

When dealing with the force of gravity between two objects, there are only two things that are important – mass, and distance. The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them

Answer:

Unbalanced

Explanation:

A cyclist decelerating uphill has unbalanced forces acting on him. An unbalanced force acting on a body has a net force which is greater than zero. When a body is accelerating or decelerating, the forces are not balanced.

Answer:

Sound waves are reflected back

Answer:

[tex]4x - 6 = 90 \\ 4x = 96 \\ \boxed{x = 24}[/tex]

Now, AD is an altitude of∆ABC

Therefore, D is the midpoint of BC

[tex]x + 7 = 2x - 15 \\ \boxed{x = 22}[/tex]

CD is (22+7) = 29 & DB is (2×22-15) = 29

[tex] \huge \boxed{\: x = 24 }\\ \huge \boxed{CD \: and \:DB= 29}[/tex]

The carbon isotope was cobined with the proton to produce the nitrogen isotope hence it is a fusion reaction.

The term nuclear fusion refers to a kind of reaction in which two nuclei fuse together to give rise to a single nuclei with the evolution of energy.

We can see that the carbon isotope was cobined with the proton to produce the nitrogen isotope hence it is a fusion reaction.

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Answer:

A. Nuclear fusion

Explanation:

got it right, trust

Answer:

12 km/hr

Explanation:

Speed= Distance/Time

Answer:

12km/h

Explanation:

average speed= Distance covered /time taken

average speed=2km/20minutes

=but 1 minutes is 60 seconds

=2km/60minutes

=12km/h