Two children sitting on a see saw such that they can't swing.what is the net torque in this situation ??? Need an appropriate answer

Answer:

B

Explanation:

Eff = output work/input work ×100

Hence, Eff = 10000/12000 × 100

Eff = 83.3%

Answer:

Liquid

Explanation:

In most liquids the particles are less densely packed giving them the ability to move around and slide past each other.

Answer:

when a two bodies A and B are moving at an angle 180° with each other then the relative velocity is the sum of bodies the velocity .i.e,

when the bodies move the opposite direction

then their relative velocity is the sum of individual velocities.

Answer:

[tex]{ \bf{potential \: energy = mass \times gravitation \times height}} \\ 350 = 17 \times 10 \times h \\ 350 = 170h \\ height = 2.06 \: metres[/tex]

Answer:

the group of units suggested by the international convention of scientists in 1960 AD to make similarties in meseurment all over the world is called SI units

Answer:

Mass M = 100 kg

Explanation:

Given;

Net force = 400 N

Initial velocity u = 66 km/h

Final velocity v = 30 km / h

Time taken = 2.5second

Find:

Acceleration of this object a

Mass M

Computation:

1 km/h = 0.277778 m/s

So,

Initial velocity u = 66 km/h = 18.333

Final velocity v = 30 km / h = 8.333

Acceleration of this object a = [v - u]/t

Acceleration of this object a = [8.333 - 18.333]/2.5

Acceleration of this object a = -4 m/s²

Mass M = Force / Acceleration of this object a

Mass M = 400 / 4

Mass M = 100 kg

Answer:

a = 1.375m/s²

Explanation:

F = m*a

55N = 40kg*a

a = 55N/40kg

a = 1.375m/s²

Answer:

The total current in the circuit is 0.8 A.

Explanation:

internal resistance of each battery = 2 ohm

Total emf of the circuit, E = E1 + E2 = 2 = 2 = 4 V

Now total internal resistance is

[tex]r = \frac{2\times 2}{2 + 2}= 1 ohm[/tex]

Total resistance, R = 4 = 1 = 5 ohm

Let the current is I.

E = I R

4 = I x 5

I = 0.8 A

Answer:

yes,

Explanation:

because a compound contains two or more chemical elements chemically bond together.

Answer: Symbol is I and unit A

Explanation: A represents Amperes

HOPE THIS HELPS!!!!!!!!

Answer:

The ratio of energy of AA battery to the car battery is 0.0156.

Explanation:

An AA battery (remote control battery) supplies the circuit with 1.5V, while a car battery supplies 12V. What is the relationship between the energy supplied between these circuit elements?

Supply by AA battery = 1.5 V

Supply by car battery = 12 V

The resistance of the circuit is R.

The energy supplied = V^2/R

The energy supplied by the AA battery is

E = 1.5 x 1.5 / R = 2.25/R

The energy supplied by the car battery is

E' = 12 x 12/ R = 144 / R

So, the ratio of

E : E' = 2.25 : 144 = 0.0156  

Answer:

The height reached is 20m, The time taken to reach 20m is 2 seconds

Explanation:

Observing the equations of motion we can see that the following equation will be most helpful for this question.

[tex]v^{2} = u^{2} + 2as[/tex]

We are given initial velocity, u

We know that the stone will stop at its maximum height, so final velocity, v

Acceleration, a

And we are looking for the displacement (height reached), s

Substitute the values we are given into the equation

[tex]0^{2} = 20^{2} + 2(10)s[/tex]

Rearrange for s

[tex]0^{2} -20^{2} =20s[/tex]

[tex]-400=20s[/tex]

[tex]\frac{-400}{20} =s[/tex]

s = -20 (The negative is just showing direction, it can be ignored for now)

The height reached is 20m

Use a different equation to find the time taken

[tex]s = vt - \frac{1}{2} at^{2}[/tex]

Substitute in the values we have

[tex]-20=(0)t - \frac{1}{2} (10)t^{2}[/tex]

Rearrange for t

[tex]-20 =0 -5 t^{2}[/tex]

[tex]\frac{-20}{-5} =t^{2}[/tex]

[tex]4 = t^{2}[/tex]

t = 2s

The time taken to reach 20m is 2 seconds

Answer:

Explanation:

If the force of 2000 N is directed towards the right and the friction is directed towards the left, the 2000 N force is positive and the other is negative. To find the resultant force:

2000 - 500 = 1500 N to the right

Answer:

Explanation:

The direction of the applied force has to be parallel to the distance an object moved in order to say that work has been done.

There are three things needed to be classified as a planet.

Pluto meets 2 of the 3.

The one it does not meet is it doesn’t “clear the neighborhood” which means a planet needs to be gravitationally dominant over all objects around it. Meaning smaller bodies ( asteroids) would either combine with the larger body making it bigger or pushing them away ( out of their orbit) so they do not collide with the larger body.

Room heaters are placed on the floor of a room so that the air heated by it rises up and sets up the convection current in the room quickly and uniformly.

Answer:

D. A

General Formulas and Concepts:

Simple Harmonic Motion

Parts of a wave

Explanation:

The amplitude is the distance from the horizon to either the crest or trough of a wave.

In layman's terms, it is how high the wave is.

The "highest" wave would be wave A.

∴ our answer is D.

Topic: AP Physics 1 Algebra-Based

Unit: SMH

Answer:

A (The wave)

Explanation:

Wave A

The book's position is changing linearly with time, so its velocity is constant. This means that the net force acting on the book in the direction parallel to the surface is

∑ F = 10.0 N - n = 0

where n is the magnitude of the normal force on the book due to the wall, and the net force perpedicular to the surface is

∑ F = f - (0.550 kg) g = 0

where f is the mag. of kinetic friction, and f = µn where µ is the coefficient of kinetic friction.

Then

• n = 10.0 N

• f = (0.550 kg) g = 5.39 N

• 5.39 N = µ (10.0 N)

==>   µ = 0.539

Answer:

Above answer

Explanation:

The book's position is changing linearly with time, so its velocity is constant. This means that the net force acting on the book in the direction parallel to the surface is

∑ F = 10.0 N - n = 0

where n is the magnitude of the normal force on the book due to the wall, and the net force perpedicular to the surface is

∑ F = f - (0.550 kg) g = 0

where f is the mag. of kinetic friction, and f = µn where µ is the coefficient of kinetic friction.

Then

• n = 10.0 N

• f = (0.550 kg) g = 5.39 N

• 5.39 N = µ (10.0 N)

==>   µ = 0.539

Answer:

[tex]W=3456 N[/tex]

Explanation:

Force 1 [tex]F_1=3456[/tex]

Force 2 [tex]F_2=2333N[/tex]

Acceleration at stage 2 [tex]a_2=0.39[/tex]

Generally the weight of the Craft W is given as

W= upward force(thrust)

Therefore

[tex]W=3456 N[/tex]

Explanation:

Yes, if force is acting on a body work done can be zero. When an object is at rest and no external force except gravity is acting on it in this case the work that would be zero as the force acting on it is perpendicular.

For example,

When an object is at rest and no external force except gravity is acting on it in this case the work that would be zero as the force acting on it is perpendicular. Therefore the displacement is zero and if displacement is zero work done would be zero.

We know that,

The work done

W=fs

Suppose that displacement is zero then,

W=f×0

W=0

The work done is zero.

Answer:

The entropy change is 45.2 kJ/K.

Explanation:

mass of water at 100 C = 2 kg

Latent heat of vaporization, L = 2260 kJ/kg

Heat is

H = m L

H = 2 x 2260 = 4520 kJ

Entropy is given by

S = H/T = 4520/100 = 45.2 kJ/K

The entropy change during the phase change of water from liquids to steam at constant pressure and same temperatures will be zero because, Δ T is zero here.

Entropy is a thermodynamic parameter determining the measure of randomness in a system. Entropy of a natural reaction or change is always increasing.

According to second third law of thermodynamics the  entropy change of the universe is positive always. At constant pressure the entropy change a of substance of m g is written as:

ΔS = m Cp ln T2/T1.

Where Cp is the specific heat capacity at constant pressure.

Here, the initial temperature and final temperature is same 100 degree celsius. Thus T2/T1 becomes 1 and log 1 is zero. Therefore, the entropy  change in this phase change is zero.

To find more on entropy, refer here:

https://brainly.com/question/13146879

#SPJ5

Answer:

The acceleration is 0.062 m/s^2.

Explanation:

mass = 12 kg

F = 30 N at 20° right

F' = 45 N at 50° left

Let the acceleration is a.

The net force is

F'' = F' cos 50° - F cos 20°

F'' = 45 x 0.643 - 30 x 0.94 = 28.94 - 28.2 = 0.74 N

According to the Newton's second law

0.74  = 12 x a

a = 0.062 m/s^2

Answer:

Explanation:

The formula for the electric field is

[tex]E=\frac{kQ}{r^2}[/tex]  where E is the magnitude of the electric field, k is Coulomb's constant, Q is the charge of the particle (which is NOT included in the formula), and r is the distance between the centers of the charges (for lack of a better description).

[tex]E=\frac{(9.0*10^9)*(6.5*10^{-6})}{(1.50)^2}[/tex] and we get, to 2 sig fig's

E = 2.6 × 10⁴ to the left (since electric fields are always pointing toward the negative charge and the electric field is to the right of the negative charge)

Answer:

0.6 m/s

Explanation:

The details of the masses and velocities are;

The mass of the ice skater, m₁ = 80 kg

The mass of the ball, m₂ = 8 kg

The speed with which the skater tosses the ball forward, v₂ = 6 m/s

Therefore;

According to the principle of conservation of linear momentum, we have;

m₁·v₁ = m₂·v₂

Where;

v₁ = The skater's reactive velocity

Therefore, we get;

80 kg × v₁ = 8 kg × 6 m/s

v₁ = 8 kg × 6 m/s/(80 kg) = 0.6 m/s

The skater's reactive velocity, v₁ = 0.6 m/s.

Answer:

climatic changes

ambient changes

human interferance and the growt of cities and human civilization

and invasive especies

Explanation:

Many different physical factors can impact the ecological tolerance of a species like:-

The portion of the abiotic factor's range of variation which a species can survive and function in is commonly defined as the tolerance range.

To know more about ecological tolerance here

https://brainly.com/question/26471341

#SPJ2

Answer:

7.3 g/cubic cm

Explanation:

You divide the mass by the volume to calculate the density of the metal.

146g ÷ 20cm³ = 7.3g/cm³

Answer:

Approximately [tex]5.19 \times 10^{-5}\; \rm N[/tex].

Explanation:

Let [tex]G[/tex] denote the gravitational constant. ([tex]G \approx 6.67 \times 10^{-11} \; \rm N \cdot kg^{-2} \cdot m^{2}[/tex].)

Let [tex]M[/tex] and [tex]m[/tex] denote the mass of two objects separated by [tex]r[/tex].

By Newton's Law of Universal Gravitation, the gravitational attraction between these two objects would measure:

[tex]\displaystyle F = \frac{G \cdot M \cdot m}{r^{2}}[/tex].

In this question: [tex]M = 7 \times 10^{22}\; \rm kg[/tex] is the mass of the moon, while [tex]m = 1\; \rm kg[/tex] is the mass of the water. The two are [tex]r = 3\times 10^{5}\; \rm km[/tex] apart from one another.

Important: convert the unit of [tex]r[/tex] to standard units (meters, not kilometers) to reflect the unit of the gravitational constant [tex]G[/tex].

[tex]\displaystyle r = 3 \times 10^{5}\; \rm km \times \frac{10^{3}\; \rm m}{1\; \rm km} = 3 \times 10^{8}\; \rm m[/tex].

[tex]\begin{aligned} F &= \frac{G \cdot M \cdot m}{r^{2}} \\ &= \frac{6.67 \times 10^{-11}\; \rm N \cdot kg^{-2}\cdot m^{2} \times 7 \times 10^{22}\; \rm kg \times 1\; \rm kg}{(3 \times 10^{8}\; \rm m)^{2}} \\ &\approx 5.19 \times 10^{-5} \; \rm N\end{aligned}[/tex].

Answer:

the answer is ....angle of reflection