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pochemuha
2 years ago
11

Two friends of different masses are on the playground. They are playing on the seesaw and are able to balance it even though the

ir masses are different.
How are they able to balance on the seesaw?

1) They are able to balance torques due to gravity.
2) They are able to balance their respective energies.
3) All of these.
4) Their densities are the same.
5) They are able to balance forces due to gravity.
6) They are able to balance their respective momenta.
Physics
1 answer:
Svetradugi [14.3K]2 years ago
6 0
1) They are able to balance the torques due to gravity.

The torque is equal fo Force * lever arm.

The force downward is due to gravity, Force = mass*gravity.

Then the heavier student will produce a bigger force downgar and he/she shall shorten the lever arm of his/her side, by placing himself closer to the rotation axis, than the lighter student.

 
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Two electrodes, separated by a distance d, in a vacuum are maintained at a constant potential difference. An electron, accelerat
Alja [10]

Answer:

Explanation:

Given that, the distance between the electrode is d.

The electron kinetic energy is Ek when the electrode are at distance "d" apart.

So, we want to find the K.E when that are at d/3 distance apart.

K.E = ½mv²

Note: the mass doesn't change, it is only the velocity that change.

Also,

K.E = Work done by the electron

K.E = F × d

K.E = W = ma × d

Let assume that if is constant acceleration

Then, m and a is constant,

Then,

K.E is directly proportional to d

So, as d increase K.E increase and as d decreases K.E decreases.

So,

K.E_1 / d_1 = K.E_2 / d_2

K.E_1 = E_k

d_1 = d

d_2 = d/3

K.E_2 = K.E_1 / d_1 × d_2

K.E_2 = E_k × ⅓d / d

Then,

K.E_2 = ⅓E_k

So, the new kinetic energy is one third of the E_k

7 0
1 year ago
A windowpane is half a centimeter thick and has an area of 1.0 m2. The temperature difference between the inside and outside sur
polet [3.4K]

To solve this problem it is necessary to apply the concepts related to the heat flux rate expressed in energetic terms. The rate of heat flow is the amount of heat that is transferred per unit of time in some material. Mathematically it can be expressed as:

\frac{Q}{t} = \frac{kA}{L} (T_H - T_C)

Where

k = 0.84 J/s⋅m⋅°C (The thermal conductivity of the material)

A = 1m^2 Area

L = 5*10^{-3}m Length

T_H= Temperature of the "hot"reservoir

T_C= Temperature of the "cold"reservoir

Replacing with our values we have that,

\frac{Q}{t} = \frac{kA}{L} (T_H - T_C)

\frac{Q}{t} = \frac{(0.84)(1)}{0.005} (15)

\frac{Q}{t} = 2520J/s

Therefore the correct answer is B.

3 0
1 year ago
The basic function of an automobile carburetor is to atomize the gasoline and mix it with air to promote rapid combustion. Assum
tatyana61 [14]

Answer:

A = 7.5 \times 10^6 m^2

Explanation:

Since volume of all the liquid is always conserved

so here we know that

V_{total} = N V

25 cm^3 = N(\frac{4}{3}\pir^3)

25 = N (\frac{4}{3} \pi (1.0 \times 10^{-5})^3)

N = 5.97 \times 10^{15}

now we know that total surface area is given as

A = N(4\pi r^2)

A = (5.97 \times 10^{15})(4\pi (1 \times 10^{-5})^2

A = 7.5 \times 10^6 m^2

5 0
2 years ago
a child hits a ball with a force of 350 N. (a) If the ball and bat are in contact for 0.12 is, what impulse does the ball receiv
Lina20 [59]

Explanation:

Given that,

Force with which a child hits a ball is 350 N

Time of contact is 0.12 s

We need to find the impulse received by the ball. The impulse delivered is given by :

J=F\times t\\\\J=350\times 0.12\\\\J=42\ N-m

So, the impulse is 42 N-m..

We know that he change in momentum is also equal to the impulse delivered.

So, impulse = 42 N-m and change in momentum =42 N-m.

7 0
2 years ago
Your film idea is about drones that take over the world. In the script, two drones are flying horizontally at the same speed and
Stella [2.4K]

Answer:

vₓ = 20 m/s,    v_{y}  = -15 m / s

Explanation:

This is a conservation of moment problem, since it is a vector quantity we can work each axis independently

The system is formed by the two drones, so the forces during the crash are internal and the moment is conserved

X axis

Initial moment. Before the crash

         p₀ = m₁ v₀ₓ + m₂ v₀ₓ

Final moment. After the crash

       p_{fx} = (m₁ + m₂) vₓ

      p₀ₓ = p_{fx}

      m₁ v₀ₓ + m₂ v₀ₓ = (m₁ + m₂) vₓ

       vₓ = (m₁ + m₂) v₀ₓ / (m₁ + m₂)

       vₓ = v₀ₓ  = 20 m/s

Y Axis

Initial

         p_{oy} = m₁ v_{oy}

Final

         p_{fy} = (m₁ + m₂) v_{y}

         p_{oy} = p_{fy}

the drom rises and when it falls it has the same speed because there is no friction    v_{oy} = -60 m/s          

 

           m₁ v_{oy} = (m₁ + m₂) v_{y}

            v_{y} = m₁ / (m₁ + m₂) v_{oy}

            v_{y}  = 1/4    60

            v_{y}  = -15 m / s

Vertical speed is down

5 0
2 years ago
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