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lord [1]
3 years ago
7

A person pushes horizontally with a force of 200. N on a 65.0 kg crate to move it across a level floor. The coefficient of kinet

ic friction is 0.270. (a) What is the magnitude of the frictional force? (b) What is the magnitude of the crate's acceleration? Use g=9.81 m/s2.
Physics
1 answer:
Alina [70]3 years ago
7 0

Answer:

a)f_k=172.17N

b)a_x=0.428m/s^2

Explanation:

The magnitude of the kinetic frictional force is given by the formula

f_k=\mu_k N

In this case, on the vertical direction the only forces are the weight and the normal force, and since the object does not move in that direction they must be equal. We have then:

f_k=\mu_k N=\mu_k W = \mu_k mg

Substituting values we get

f_k=\mu_k mg=(0.27)(65Kg)(9.81m/s^2)=172.17N

On the horizontal direction the only forces are the one the person exerts (F_p) and the kinetic friction opposing it, so the net force is:

F_x=F_p-f_k

We apply then Newton's 2nd Law to calculate the acceleration of the object in the horizontal direction:

ma_x=F_x=F_p-f_k

a_x=\frac{F_p-f_k}{m}

And substituting values we have

a_x=\frac{200N-172.17N}{65Kg}=0.428m/s^2

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Fofino [41]

Explanation: Velocity is the displacement of an object during a specific unit of time. Two measurements are needed to determine velocity. Displacement and time. Displacement includes a direction, so velocity also includes a direction. Speed with direction. Velocity can be an average velocity or an instantaneous velocity. Units for velocity are the same as for speed: m/s, km/h, and mph. Delta x(Δx) is the symbol used for displacement. Delta (Δ) means to "change in." Δx means to "change in position." Δx is calculated by final position minus initial position. Velocity formula: → v=Δx/t as a fraction.

v=Δx/t

v=\frac{xf-xi}{t}= \frac{60m}{2}=30m

<em><u>Final answer is 30.</u></em>

Hope this helps!

Thanks!

Have a great day!

-Charlie

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3 years ago
Someone pls help me with this!
Lina20 [59]

Answer:

<em>F=8.87 N</em>

Explanation:

<u>Coulomb's Law </u>

The electrostatic force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.

Written as a formula:

\displaystyle F=k\frac{q_1q_2}{d^2}

Where:

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