Which of newtons laws accounts for the following statement " Negative acceleration is proportional to applied braking force "

How is it possible you can feel heat from the sun?

sergey [27]

there are three ways by which we can transfer heat from one place to other

1. Conduction

In this method of heat transfer heat can be transferred from one place to other without actual movement of medium molecules. This is possible in solid conducting mediums

2. Convection

Here heat energy is carried away along with the medium molecules where medium molecules can move from one place to other while heat is transferred. It is possible in liquid and gas but not possible in solids

3. Radiation

In this mode of heat transfer we do not require any medium and here heat transferred by electromagnetic waves

So we can feel heat from sun in form of electromagnetic waves and it is the fastest way to transfer the heat also it do not require any medium

8 0

3 years ago

The mass of Object 2 is double the mass of Object 5. The mass of Object 4 is half of the mass of Object 5 and the mass of Object

SVETLANKA909090 [29]

This is a great problem if you like getting tied up in knots
and making smoke come out of your brain.

I found that it makes the problem a lot easier if I give the objects some
numbers. I'm going to say that the mass of Object 5 is 20 clods.

Let the mass of Mass of Object 5 be 20 clods .

Then . . .

-- The mass of Object 2 is double the mass of Object 5 = 40 clods.

-- The mass of Object 4 is half of the mass of Object 5 = 10 clods.
and
-- the mass of Object 3 is half of the mass of Object 4 = 5 clods.

So now, here are the masses:

Object #1 . . . . . unknown
Object #2 . . . . . 40 clods
Object #3 . . . . . 5 clods
Object #4 . . . . . 10 clods
Object #5 . . . . . 20 clods .

Now let's check out the statements, and see how they stack up:

Choice-A:
Object 3 and Object 5 exert the same gravitational force on Object 1.
Can't be.
Objects #3 and #5 have different masses, so they can't both
exert the same force on the same mass.

Choice-B.
Object 2 and Object 4 exert the same gravitational force on Object 1.
Can't be.
Objects #2 and #4 have different masses, so they can't both
exert the same force on the same mass.

Choice-C.
The gravitational force between Object 1 and Object 2 is greater than
the gravitational force between Object 1 and Object 4.
Yes ! Yay !
Object-2 has more mass than Object-4 has, so it must exert more force on
ANYTHING than Object-4 does, (as long as the distances are the same).

Choice-D.
The gravitational force between Object 1 and Object 3 is greater than the gravitational force between Object 1 and Object 5.
Can't be.
Object-3 has less mass than Object-5 has, so it must exert less force on
ANYTHING than Object-4 does, (as long as the distances are the same).

Conclusion:
If the DISTANCE is the same for all the tests, then Choice-C is
the only one that can be true.

8 0

3 years ago

A constant electric field with magnitude 1.50 ✕ 103 N/C is pointing in the positive x-direction. An electron is fired from x = −

romanna [79]

Answer:

The speed of electron is $1.5\times10^{7}\ m/s$

Explanation:

Given that,

Electric field $E=1.50\times10^{3}\ N/C$

Distance = -0.0200

The electron's speed has fallen by half when it reaches x = 0.190 m.

Potential energy $P.E=5.04\times10^{-17}\ J$

Change in potential energy $\Delta P.E=-9.60\times10^{-17}\ J$ as it goes x = 0.190 m to x = -0.210 m

We need to calculate the work done by the electric field

Using formula of work done

$W=-eE\Delta x$

Put the value into the formula

$W=-1.6\times10^{-19}\times1.50\times10^{3}\times(0.190-(-0.0200))$

$W=-5.04\times10^{-17}\ J$

We need to calculate the initial velocity

Using change in kinetic energy,

$\Delta K.E = \dfrac{1}{2}m(\dfrac{v}{2})^2+\dfrac{1}{2}mv^2$

$\Delta K.E=\dfrac{-3mv^2}{8}$

Now, using work energy theorem

$\Delta K.E=W$

$\Delta K.E=\Delta U$

So, $\Delta U=W$

Put the value in the equation

$\dfrac{-3mv^2}{8}=-5.04\times10^{-17}$

$v^2=\dfrac{8\times(5.04\times10^{-17})}{3m}$

Put the value of m

$v=\sqrt{\dfrac{8\times(5.04\times10^{-17})}{3\times9.1\times10^{-31}}}$

$v=1.21\times10^{7}\ m/s$

We need to calculate the change in potential energy

Using given potential energy

$\Delta U=-9.60\times10^{-17}-(-5.04\times10^{-17})$

$\Delta U=-4.56\times10^{-17}\ J$

We need to calculate the speed of electron

Using change in energy

$\Delta U=-W=-\Delta K.E$

$\Delta K.E=\Delta U$

$\dfrac{1}{2}m(v_{f}^2-v_{i}^2)=4.56\times10^{-17}$

Put the value into the formula

$v_{f}=\sqrt{\dfrac{2\times4.56\times10^{-17}}{9.1\times10^{-31}}+(1.21\times10^{7})^2}$

$v_{f}=1.5\times10^{7}\ m/s$

Hence, The speed of electron is $1.5\times10^{7}\ m/s$

4 0

3 years ago

. A bird is flying with a speed of 18.0 m/s over water when it accidentally drops a 2.00 kg fish. If the altitude of the bird is

zysi [14]

V^2 = u^2 + 2gr, where v - speed, u - initial speed=0, r - displacement (or height)
v^2 = 0 + 2*10*5.4
v = 10.2 m/s

4 0

3 years ago

Read 2 more answers

4. Explain the doppler effect. Be sure to talk about how the wave changes, the perceived change hear by a person that an emitted

Lemur [1.5K]

Answer:

4) The Doppler effect is the frequency change that occurs in a wave by the relative movement of the emitter and the observer

5) Sound originates from a repetitive movement of air molecules

6) The principle of stable superposition that if the medium complies with the elastic regime, the waves traveling in it can be added

Explanation:

4) The Doppler effect is the frequency change that occurs in a wave by the relative movement of the emitter and the observer. In the specific case of the fixed observer, each wave that is emitted travels at a constant speed, but as the emitter approaches the next wave lLa in less time, so the wave maxima are closer to each other

v = λ’ f’

λ‘=λ -Δλ = λ - vs / f

f’= v / λ’ = v / (λ - vs / f) = v / (v / f - vs / f)

f ‘= f v / (v-vs)

5) Sound originates from a repetitive movement of air molecules, this movement creates a longitudinal wave, which we call sound. It is characterized by the air volume module and its density

6) The principle of stable superposition that if the medium complies with the elastic regime, the waves traveling in it can be added

y total = y₁ + y₂

Let's see as an example two waves of the same amplitude that travel in the same direction, if this wave the maximums coincide they add up obtaining that the maximums are twice the amplitude

If the wave goes in the most directive but the maximum of one coincides with the minimum in the other, the sum gives zero,

The wave travels in the opposite direction, in this case the resulting wave in constant in time and we call it resonance

7 0

3 years ago