A machine that operates a ride at the fair requires 2500 J to lift a 294 N child 5.0 m. What is the efficiency of this machine?

Answer:

122.4

Explanation:

Answer:

The true statements are;

F, D, E, J

Explanation:

F and D are true because they agree with our knowledge of electrostatic interaction. Like charges repel while unlike charges attract. Statements B and C are not in line with the principles of electrostatics because neutral objects do not interact with charged bodies in an electric field.

E and J are true for the same reasons outlined above. Remember that like charges always repel each other and unlike charges always attract each other.

Answer:

Explanation:

The mass of the encyclopedia can be found by using the formula

[tex]m = \frac{f}{a} \\ [/tex]

f is the force

a is the acceleration

From the question we have

[tex]m = \frac{15}{5} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

d

Explanation:

Answer: The Sun's energy is more concentrated on the equator than the poles. This is because the Sun's energy (in the form of warmth) is more direct at the equator, and less direct at the poles.

Explanation: You can see this with a flashlight. When you point the flashlight directly toward a tale, the light is very concentrated and right. However, when you point the flashlight toward the table at an angle, the light becomes more spread out and less concentrated.  This is why even though sometimes the North Poles and South Poles have 24 hours of sunlight, it never actually reaches a high temperature and instead, keeps it's cold temperature.

Answer:

The magnitude and direction of the resultant is 8.66 N and [tex]60^{\circ}[/tex] south of East.

The magnitude and direction the equilibrant is 8.66 N and [tex]60^{\circ}[/tex] North of West respectively.

Explanation:

Let

[tex]P=5\ \text{N}\ \text{south}[/tex]

[tex]Q=5\ \text{N}\ 30^{\circ}\ \text{south of east}[/tex]

[tex]\theta[/tex] = Angle between P and Q = [tex]60^{\circ}[/tex]

Magnitude of resultant

[tex]R=\sqrt{P^2+Q^2+2PQ\cos\theta}\\\Rightarrow R=\sqrt{5^2+5^2+2\times 5\times 5\cos60^{\circ}}\\\Rightarrow R=8.66\ \text{N}[/tex]

Direction is given by

[tex]\theta=\tan^{-1}\dfrac{Q\sin\theta}{P+Q\sin\theta}\\\Rightarrow \theta=\tan^{-1}\dfrac{5\sin60^{\circ}}{5+5\sin60^{\circ}}\\\Rightarrow \theta=30^{\circ}[/tex]

The magnitude and direction of the resultant is 8.66 N and [tex]30^{\circ}+30^{\circ}=60^{\circ}[/tex] south of East.

The magnitude and direction the equilibrant is 8.66 N and [tex]60^{\circ}[/tex] North of West.

Answer:

Explanation:

Step one:

given data

initial speed u= 5m/s

time t= 3seconds

acceleration due to gravity g= 9.8m/s^2

Required:

the final velocity v

Step two:

applying the first equation of motion

v=u+gt-----------we used + because the ball is falling with gravity

v=5+9.8*3

v=5+29.4

v=34.4

The final velocity is 34.4m/s

Answer:

-34.4

Explanation:

the person above had the right approach but it would be negative as it is in a downwards motion

Answer:

The diagram doesn’t tell you anything about the force on the asteroid. It only gives information about the force on the planet and the moon.

Explanation:

Answer:

Wavelength  = 0.48 m (Approx)

Explanation:

Given:

Speed of sound = 340 m/s

Frequency = 706 hz

Find:

Wavelength

Computation:

Wavelength  = Speed of sound / Frequency

Wavelength  = 340 / 706

Wavelength  = 0.48 m (Approx)

Answer:

Explanation:

Initial velocity , u = 27 m/s

displacement before stop,  s = 41.5 m .

final velocity,  v = 0

acceleration a = ?

v² = u² + 2 a s

0 = 27² + 2 x a x 41.5

a = - 27² / 2 x 41.5

= - 8.78 m /s

Answer:

[tex]a=18.51\ m/s^2[/tex]

Explanation:

Given that,

Initial speed, u = 0 km/h

Final speed, v = 100 km/h = 27.77 m/s

Time, t = 1.5 s

We need to find the average acceleration of this motorcycle. It is equal to the rate of change of velocity and it is given by :

[tex]a=\dfrac{v-u}{t}\\\\a=\dfrac{v}{t}\\\\a=\dfrac{27.77\ m}{1.5\ s}\\\\a=18.51\ m/s^2[/tex]

So, the acceleration of the motorcycle is [tex]18.51\ m/s^2[/tex].

Answer:

Explanation:

hope it helps:)

Answer:

C

Explanation:

three bricks means 3 times the weight, so 6/3=2

Answer:

Answer:

Explanation:

a helmet is used for our safety this  piece of equipment is used to protect us from getting any injury's on our heads such as concussions getting a cut on your head etc.

Answer:

27.8 mph

Explanation:

May I have brainliest please? :)

The answer is option c - It will divide in half to form two new cells..

Explanation:

The sentence that best describes what happened during cell growth is ;

( D ) It will become larger by taking in nutrients

As the yeast cells begin to grow ( i.e. cell growth ), they will require more nutrients and as they take in the necessary nutrients they will gradually increase in size ( becoming larger ) which is a vital sign of cell growth and development, which will be seen in the yeast cells as they undergo cell growth.

The production of offsprings with a mate does not describe an activity that occurs in cell growth.  

Hence we can conclude that The sentence that best describes what happened during cell growth is, It will become larger by taking in nutrients.

Learn more : https://brainly.com/question/24893507

Answer:

This can spread their weight.

Explanation:

The ladder has a much larger surface area than the firefighter. Hence, his weight is spread out much more than usual, decreasing the pressure on the ice, preventing the ice from breaking/cracking.

Hope this helped!

Answer:

Potential gravitational energy is the energy that the body has due to the Earth's gravitational attraction. In this way, the potential gravitational energy depends on the position of the body in relation to a reference level.

Explanation:

Answer:

Following are the solution to this question:

Explanation:

Given value:

[tex]m_s= 4.00 \times 10^{-2} \ kg \\\\L_v=2256 \times 10^{3} \ \frac{J}{kg}\\\\m_w= 0.2 \ kg\\\\\Delta T= 50^{\circ}[/tex]

In point A:

[tex]Q_{Steam}=m_s \ L_v[/tex]

            [tex]=0.04 \times 2256 \times 10^{3}\\\\=9.02 \times 10^4 \ J[/tex]

[tex]Q_{water}= m_w \ c_w \ \Delta T\\\\[/tex]

           [tex]=0.2 \times 4190 \times 50\\\\=4.19 \times 10^4 \ J[/tex]

[tex]Q_{steam}> Q_{water}[/tex], that's why the final temperature is [tex]= 100^{\circ}[/tex]

In point B:

[tex]\to \Delta m_s L_v=m_w\ c_w \Delta T\\\\\to \Delta m_s \times 2256\times 10^3= 0.2 \times 4190 \times 50\\\\\to \Delta m_s= 1.86 \times 10^{-2} \ kg\\\\\to m_s = 2.14 \times 10^{-2} \ kg\\\\\to liquid \ left = 0.2+ 2.14 \times 10^{-2} = 2.34 \times 10^{-2} \\[/tex]

Answer: C

Explanation: You always have weight pushing down and natural force pushing up to neutralize those forces. The you add in friction and that’s how you find the answer. Plus I got it right in my quiz

Answer:

[tex]\boxed {\boxed {\sf d= 5 \ g/cm^3}}[/tex]

Explanation:

Density can be found by dividing the mass by the volume.

[tex]d=\frac{m}{v}[/tex]

The mass of the quartz is 30 grams and the volume is 6 cubic centimeters.

[tex]m=30 \ g \\v= 6 \ cm^3[/tex]

Substitute the values into the formula.

[tex]d=\frac{30 \ g}{6 \ cm^3}[/tex]

Divide.

[tex]d= 5 \ g/cm^3[/tex]

The density of this piece of quartz is 5 grams per cubic centimeter.

Answer:

The force to get the plane moving, and to balance the friction so it does not stop, is provided by the propeller. However, the wheels provide the acceleration of the car.

Explanation:

[tex]{\green{\underline{\textsf{\textbf{Case 2 :When lighter part of a mixture is unwanted and the husk is useful. }}}}}[/tex]

[tex]{\green{\underline{\textsf{\textbf{Explanation : }}}}}[/tex]

As we know that, Winnowing is used when the lighter particles is required to remove. Hence, in Case 2 the lighter part is removed and the remaining is needed.

Answer:

.78 m/s north

Explanation:

Pls give brainliest if I correct

Answer:

Mass, m = 32 kg

Explanation:

Given that,

Force, F = 2000 N

The change in velocity, (v-u) = 50 m/s

Time, t = 0.8 s

We need to find the mass of the ball. The net force acting on an object is given by :

F = ma

Where a is acceleration

[tex]F=\dfrac{m(v-u)}{t}\\\\m=\dfrac{Ft}{(v-u)}\\\\m=\dfrac{2000\times 0.8}{50}\\\\m=32\ kg[/tex]

So, the mass of the ball is 32 kg.

Answer:

D. its acceleration is zero

Explanation:

Acceleration can be defined as the rate of change of the velocity of an object with respect to time.

This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.

Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.

Mathematically, acceleration is given by the equation;

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

In this scenario, a stone is thrown straight up. While the stone is rising its acceleration is zero because it's initial velocity is zero and it's until the stone reaches its highest point before the acceleration becomes constant and acting downward.

Answer:

35.28m/s; 63.50m

Explanation:

Given the following data;

Time, t = 3.6 secs

Since it's a free fall, acceleration due to gravity = 9.8m/s²

Initial velocity, u = 0

To find the final velocity, we would use the first equation of motion;

[tex] V = u + at[/tex]

Substituting into the equation, we have;

[tex] V = 0 + 9.8 * 3.6[/tex]

V = 35.28m/s

Therefore, the final velocity of the penny is 35.28m/s.

To find the height, we would use the second equation of motion;

[tex] S = ut + \frac {1}{2}at^{2}[/tex]

Substituting the values into the equation;

[tex] S = 0(3.6) + \frac {1}{2}*9.8*(3.6)^{2}[/tex]

[tex] S = 0 + 4.9*12.86[/tex]

[tex] S = 0.5 *36[/tex]

S = 63.50m

Therefore, the height of the tower is 63.50m.