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4 years ago

What is friction? (explain if full sentences)

2 answers:

7 0

The resistance that one surface or object encounters when moving over another. The action of one surface or object rubbing against another.

Softa [21]4 years ago

4 0

Answer: what comes to mind when we hear the word "Friction" ?

Basically friction is a "Force" that opposes an intend(ing) motion.

Explanation:

By motion I mean movement.

By force I mean a body that carries with it energy.

So to understand this better, just see it as a force(thing) that prevents or stops you from taking action.

You might be interested in

An early method of measuring the speed of light makes use of a rotating slotted wheel. A beam of light passes through one of the

Readme [11.4K]

Answer:

4.7 x 10³ rad / s

Explanation:

During the time light goes and comes back , one slot is replaced by next slot while rotating before the light source

Time taken by light to travel a distance of 2 x 500 m is

= (2 x 500) / 3 x 10⁸

= 3.333 x 10⁻⁶ s .

In this time period, two consecutive slots come before the source of light one after another by rotation. There are 400 slots so time taken to make one rotation

= 3.333 x 10⁻⁶ x 400

= 13.33 x 10⁻⁴ s

This is the time period so

T = 13.33 X 10⁻⁴

Angular speed

= 2π / T

= $\frac{2\times3.14}{13.33\times10^{-4}}$

4.7 x 10³ rad / s

5 0

3 years ago

Explain how we use a spectrometer to help us determine what stars and planets are made of?

BaLLatris [955]

We use a spectrometer to help us determine what stars and planets are made of by passing a light through various chemical elements, different spectral patterns are created. By matching those patterns up to patterns generated in a laboratory environment we can tell what the composition of a distant star or planet is.

4 0

3 years ago

A plane flies 125 km/hr at 25 degrees north of east with a wind speed of 36 km/hr at 6 degrees south of east. What is the result

nasty-shy [4]

Answer:

V = 156.85 Km/h

Explanation:

Speed of plane = 125 Km/h

angle of plane= 25° N of E

Speed of wind = 36 Km/h

angle of plane = 6° S of W

Horizontal component of the velocity

V_x = 125 cos 25° + 36 cos 6°

V_x = 149 Km/h

Vertical component of the velocity

V_y = 125 sin 25° - 36 sin 6°

V_y = 49 Km/h

Resultant of Velocity

$V = \sqrt{V_x^2 + V_y^2}$

$V = \sqrt{149^2 + 49^2}$

V = 156.85 Km/h

the resulting velocity of the plane is equal to V = 156.85 Km/h

5 0

3 years ago

A tourist drops a rock from rest from a guard rail overlooking a valley. What is the velocity of the rock at 4.0 s? What is the

3241004551 [841]

At the end of 4.0 s the velocity of the rock is 39.24 m/s and its displacement from the point where it was dropped is 78.48 m.

The rock dropped from the guard rail is a freely falling body and is accelerated downwards under acceleration due to gravity.

To calculate the velocity after t=4.0 s, use the equation of motion,

$v=u+at$

Here, <em>u </em>is the rock's initial velocity, which is zero. It falls under acceleration due to gravity, hence a =g=9.81 m/s².

Therefore,

$v=u+at\\ v=gt\\ =(9.81m/s^2)(4.0s)\\ =39.24m/s$

If it falls through a distance <em>s, </em>then, use the equation,

$s=ut+\frac{1}2} gt^2$

Therefore,

$s=ut+\frac{1}2} gt^2\\ s=\frac{1}2} gt^2\\ =\frac{1}2}(9.81m/s^2)(4.0s)^2\\ =78.48 m$

Thus, after 4.0 s, the rock has a downward velocity of 39.24 m/s and it would have traveled a distance of 78.48m.

7 0

3 years ago

Another coin is thrown up into the air and hit the ground after 6s with a velocity of -60 m/s after experiencing an acceleration

Grace [21]

Answer:

Vf = Vi + a t fundamental equation

-60 m/s= Vi - 9.8 m/s^2 * 6 sec taking upward direction as positive

Vi =58.8 m/s - 60 m/s = -1.2 m/s so the coin was initially thrown downward

As a check take the downward direction as positive

Vf = 1.2 m/s + 58.8 m/s = 60 m/s

7 0

3 years ago