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2 years ago

A bulldozer does 45,000 joules of work to push a boulder a distance of 30 meters.

Physics

1 answer:

Andrew [12]2 years ago

7 0

Answer:

1500N

Explanation:

we have ,

w= f*d

45,000 =f * 30

f=45000/30

f=1500N..

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What is a description of compounds?

elena-14-01-66 [18.8K]

Compounds are elements that are chemically combined, like water for example (it’s both hydrogen and oxygen.)

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2 years ago

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What do we mean when we say that two light rays striking a screen are in phase with each other? What do we mean when we say that

galina1969 [7]

Answer: When the electric field due to one is a maximum, the electric field due to the other is also a maximum, and this relation is maintained as time passes. They alternatively reinforce and cancel each other.

Explanation:

In a wave, the phase, is an arbitrary time reference, used to locate a given point of the wave in time, within a cycle.

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2 years ago

Two cars are moving towards each other and sound emitted by first car with real frequency of 3000 hertz is detected by a person

sertanlavr [38]

Answer:

v ’= 21.44 m / s

Explanation:

This is a doppler effect exercise that changes the frequency of the sound due to the relative movement of the source and the observer, the expression that describes the phenomenon for body approaching s

f ’= f (v + v₀) / (v- $v_{s}$ )

where it goes is the speed of sound 343 m / s, v_{s} the speed of the source v or the speed of the observer

in this exercise both the source and the observer are moving, we will assume that both have the same speed,

v₀ = v_{s} = v ’

we substitute

f ’= f (v + v’) / (v - v ’)

f ’/ f (v-v’) = v + v ’

v (f ’/ f -1) = v’ (1 + f ’/ f)

v ’= (f’ / f-1) / (1 + f ’/ f) v

v ’= (f’-f) / (f + f’) v

let's calculate

v ’= (3400 -3000) / (3000 +3400) 343

v ’= 400/6400 343

v ’= 21.44 m / s

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2 years ago

Plz help me ASAP How does sound travel from its source to your ear??? 1. By changes in air pressure 2. By vibrations in wires or

Sholpan [36]

Answer:

2. By vibrations in wires or strings.

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3 years ago

Kinetic energy varies jointly as the mass and the square of the velocity. A mass of 1515 grams and velocity of 77 centimeters pe

Alexus [3.1K]

Answer:

The second kinetic energy is 162 J.

Explanation:

Given that,

Mass, $m_1=15\ g$

Velocity, $v_1=7\ cm/s$

Kinetic energy, $K_1=147\ ergs$

Mass, $m_2=10\ g$

Velocity, $v_2=9\ cm/s$

We need to find kinetic energy $K_2$ . Kinetic energy is given by :

$K=\dfrac{1}{2}mv^2$

So,

$\dfrac{K_1}{K_2}=\dfrac{m_1}{m_2}\times \dfrac{v_1^2}{v_2^2}\\\\K_2=\dfrac{K_1}{\dfrac{m_1}{m_2}\times \dfrac{v_1^2}{v_2^2}}\\\\K_2=\dfrac{147}{\dfrac{15}{10}\times \dfrac{7^2}{9^2}}\\\\K_2=162\ J$

So, the second kinetic energy is 162 J.

4 0

2 years ago