(NO LINKS) A carpenter strikes a nail with a hammer, pushing it into wood.

When you speak or sing, you force air through your ?

zaharov [31]

You force air from your lungs up through your larynx which is commonly called the voicebox

6 0

4 years ago

A spaceship ferrying workers to moon Base i takes a straight-line pat from the earth to the moon, a distance of 384,000km, Suppo

GrogVix [38]

Answer:

95.78125%

18000 m/s

22233.33 seconds

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

$v=u+at\\\Rightarrow v=0+20\times 15\times 60\\\Rightarrow v=18000\ m/s$

The velocity of the rocket at the end of the first 15 minutes is 18000 m/s which is the maximum speed of the rocket in the complete journey.

Distance traveled while speeding up

$s=ut+\dfrac{1}{2}at^2\\\Rightarrow s=0\times t+\dfrac{1}{2}\times 20\times 900^2\\\Rightarrow s=8100000\ m$

Distance traveled while slowing down

$s=18000\times 900+\dfrac{1}{2}\times -20\times 900^2\\\Rightarrow s=8100000\ m$

Distance traveled during constant speed

$384000000-(2\times 8100000)=367800000\ m$

Fraction

$\dfrac{367800000}{384000000}\times 100=95.78125\ \%$

Fraction of the total distance is traveled at constant speed is 95.78125%

Time taken at constant speed

$t=\dfrac{367800000}{18000}=20433.33\ s$

Total time taken is $900+20433.33+900=22233.33\ s$

6 0

3 years ago

Tranh slowed his skateboard as he

ICE Princess25 [194]

Answer:

Explanation:

Given parameters:

Initial velocity = 8m/s

Final velocity = 2m/s

Time taken = 3seconds

Unknown and solution:

1. Is he accelerating or decelerating?

Tranh is obviously decelerating in this period. This is negative form of acceleration in which the speed reduces as the body comes to a stop.

Deceleration is a negative change in velocity with time i.e a body is reducing its velocity as time is changing.

2. What is the value?

Mathematically;

Deceleration = $\frac{Final velocity - initial velocity}{time taken}$

Deceleration = $\frac{2 -8}{3}$

= -2m/s²

3 0

3 years ago

What is the period of the kinetic or the potential energy change if the period of position change of an object attached to a spr

mylen [45]

Answer: 2.2 s

Explanation:

This is a simple harmonic motion problem. A simple Harmonic motion can be defined as special type of periodic oscillation where the restoring force is directly proportional to the displacement. The restoring force then acts in the direction opposite to the displacement.

All simple harmonic motion is sinusoidal.

PERIOD is the time required to complete a full cycle.

From the question, the period of position change of an object attached to a spring is 4.4 s. There are two potential energy and two kinetic energy maxima per period, therefore, we have 4.4/2 = 2.2 s.

3 0

3 years ago

Which Lewis dot diagram shows an atom that needs 2 more electrons in its outermost shell?

sergiy2304 [10]

Answer: Option (c) is the correct answer.

Explanation:

Atomic number of hydrogen is 1 and one dot in its lewis structure displays only one electron. So, in order to complete its octet it needs one more electron.

Atomic number of carbon is 6 and its electronic distribution is 2, 4. Carbon needs 4 more electrons in order to complete its octet.

Atomic number of oxygen is 8 and its electronic distribution is 2, 6. In order to complete octet, oxygen needs 2 more electrons.

Atomic number of fluorine is 9 and its electronic distribution is 2, 7. In order to complete octet, fluorine needs 1 more electron.

Hence, we can conclude that out of the given options, lewis dot structure of oxygen atom needs 2 more electrons in its outermost shell.

8 0

4 years ago

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