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alukav5142 [94]

2 years ago

11

A bicycle and its rider have a combined mass of 80 kg and a speed of 6 m/s. What is the magnitude of the average force needed to

bring the bicycle and its rider to a stop in 4 seconds?

2 answers:

anygoal [31]2 years ago

6 0

Answer: 120N

Explanation:Please see attachment for explanation

lisabon 2012 [21]2 years ago

4 0

The magnitude is 24 meter

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Explain this statement: Cells are the basic unit of structure and function in organisms.

Aleonysh [2.5K]

Cells are the smallest level of a living organism.

8 0

2 years ago

PLZ HELPPPPP!! i'll give brainliest

kati45 [8]

Answer:

12N to the right.

Explanation:

There is a force of 12N upwards and a force of 12N downwards: these cancel out.

Assign a negative value to forces towards the left, and a positive value to the forces towards the right: -3N and +15N

Combine them: -3N+15N = 12N

The net force has a magnitude of 12N, and since our answer was positive, it acts towards the right.

5 0

2 years ago

When a carpenter shuts off his circular saw, the 10.0 inch diameter blade slows from 4250 rpm to 0.00 in 4.00 s. (a) What is the

MaRussiya [10]

Answer:

(a) $\alpha=-111.26rad/s$

(b) $s=4450.6in$

(c) $8.66in$

Explanation:

First change the units of the velocity, using these equivalents $1rev=2\pi rad$ and $1 min =60s$

$4250rpm(\frac{2\pi rad}{1rev})(\frac{1 min}{60 s} )=445.06rad/s$

The angular acceleration $\alpha$ the time rate of change of the angular speed $\omega$ according to:

$\alpha=\frac{\Delta \omega}{\Delta t}$

$\Delta \omega=\omega_i-\omega_f$

Where $\omega_i$ is the original velocity, in the case the velocity before starting the deceleration, and $\omega_f$ is the final velocity, equal to zero because it has stopped.

$\alpha=\frac{\Delta \omega}{\Delta t} =\frac{\omega_i-\omega_f}{4}\frac{0-445.06}{4} =\frac{-445.06}{4} =-111.26rad/s$

b) To find the distance traveled in radians use the formula:

$\theta = \omega_i t + \frac{1}{2} \alpha t^2$

$\theta = 445.06 (4) + \frac{1}{2}(-111.26) (4)^2=1780.24-890.12=890.12rad$

To change this result to inches, solve the angular displacement $\theta$ for the distance traveled $s$ ( $r$ is the radius).

$\theta=\frac{s}{r} \\s=\theta r$

$s=890.12(5)=4450.6in$

c) The displacement is the difference between the original position and the final. But in every complete rotation of the rim, the point returns to its original position. so is needed to know how many rotations did the point in the 890.16 rad of distant traveled:

$\frac{890.12}{2\pi}=141.6667$

The real difference is in the 0.6667 (or 2/3) of the rotation. To find the distance between these positions imagine a triangle formed with the center of the blade (point C), the initial position (point A) and the final position (point B). The angle $\gamma=\frac{2\pi}{3}=\frac{360^o}{3}=120$ is between the two sides known. Using the theorem of the cosine we can find the missing side of the the triangle(which is also the net displacement):

$c^2=a^2+b^2-2abcos(\gamma)$

$c^2=5^2+5^2-2(5)(5)cos(\frac{2\pi}{3} )\\c^2=25+25+25\\c^2=75\\c=5\sqrt{3}=8.66in$

4 0

3 years ago

A stationary boat in the ocean is experiencing waves from a storm. the waves move at 56 km/h and have a wavelength of 160 m, bot

Lera25 [3.4K]

The wavelength $\lambda$ of the wave is 160 m, and this is the distance between two consecutive crests. The boat is located at a crest of the wave, this means that the first trough is located 80 meters from the boat (because the distance between a crest and a trough is half the wavelength).

The speed of the wave is
$v=56 km/h = 15.6 m/s$
so the time the boat takes to reach the first trough is
$t= \frac{S}{v} = \frac{80 m}{15.6 m/s}=5.1 s$

5 0

3 years ago

Five groups of four vectors are shown below. All magnitudes of individual vectors are equal. Please rank the groups based on the

valkas [14]

With the addition of vectors we can find that the correct answer is:

C) Q> P > R = S > T

The addition of vectors must be done taking into account that they have modulus and direction. The analytical method is one of the easiest methods, the method to do it is:

Set a Cartesian coordinate system

Decompose vectors into their components in a Cartesian system

Perform the algebraic sums on each axis

Find the resultant vector using the Pythagoras' Theorem to find the modulus and trigonometry to find the direction.

In this exercise indicate that the modulus of all vectors is the same, suppose that the value of the modulus is A.

We fix a Cartesian coordinate system with the horizontal x axis and the vertical y axis, we can see that we do not need to perform any decomposition, so we perform the algebraic sums

Diagram P

x-axis

x = 2A

y-axis

y = 2A

The modulus of the resulting vector can be found with the Pythagorean Theorem

P = $\sqrt{x^2+y^2}$

P = $\sqrt{4A^2 +4A^2 }= \sqrt{8} \ A$

P = 2 √2 A

Diagram Q

x-axis

x = 3A

y-axis

y = A

Resulting

Q = $\sqrt{x^2+y^2}$

Q = $\sqrt{9A^2 + A^2 }$

Q = $\sqrt{10} \ A$

Diagram R

x- axis

x = 0

y-axis

y = 2 A

Resulting

R = $\sqrt{4A^2 + 0}$

R = $\sqrt{4} \ A$

Diagram S

x-axis

x = 2 A

y-axis

y = 0

Resulting

S = 2A

Diagram T

x- axis

x = 0

y-axis

y = 0

Resultant T = 0

We order the diagram from highest to lowest

Q> P> R = S> T

When reviewing the different answers, the correct one is:

C. Q> P> R = S> T

Learn more about adding vectors here:

brainly.com/question/14748235

5 0

1 year ago