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sesenic [268]
3 years ago
12

a 0.4 kg block rests on a desk. the coefficient of static friction is 0.2. You push the side of the block but do not have a spri

ng scale to measure the force you use. the block does not move. which statement is true about the force of static friction?
Physics
2 answers:
ladessa [460]3 years ago
7 0
Static friction is greater than Applied force
saw5 [17]3 years ago
6 0

Answer:

D. It is no smaller than 0.78N

Explanation:

The question is incomplete. These are all the options :

A. It is no larger than 0.78N

B. It is 0.78N

C. It is 0.08N

D. It is no smaller than 0.78N

To solve this problem, we have the data of :

m=0.4kg

Where ''m'' is the mass of the block

μ = 0.2

Where ''μ'' is the coefficient of static friction

If we want to find the magnitude of the force of static friction we need to use the following equation :

F_{sf}= μ.F_{N} (I)

Where ''F_{N}'' is the normal force that the desk exerts on the block. Its magnitude is equal to the weight (because we suppose that the block rests horizontally on the desk).

The weight ''W'' can be calculated as :

W=m.g

Where ''m'' is the mass and ''g'' is the acceleration due to gravity.

The value of ''g'' is

g=9.81\frac{m}{s^{2}}

The weight of the block is

W=(0.4kg).(9.81\frac{m}{s^{2}})

W=3.924N

Now, the weight is equal to the normal force ⇒

W=F_{N}=3.924N

Using the equation (I) :

F_{sf}=(0.2).(3.924N)

F_{sf}=0.7848N

The correct option is D. It is no smaller than 0.78N

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La distancia por carretera de Chitré a Parita es de 12 km; exprese en pies ésta distanciaLa distancia por carretera de Chitré a
densk [106]

Answer:

La distancia por carretera de Chitré a Parita es de 12 km o 39370.08 pies.

Explanation:

La regla de tres es una forma de resolver problemas de proporcionalidad entre tres valores conocidos y un valor desconocido, estableciendo una relación de proporcionalidad entre todos ellos.

Si la relación entre las magnitudes es directa, es decir, cuando una magnitud aumenta, también lo hace la otra (o cuando una magnitud disminuye, también lo hace la otra), se debe aplicar la regla directa de tres. Para resolver una regla directa de tres, se debe seguir la siguiente fórmula, siendo a, b y c los valores conocidos y x el valor a determinar:

a ⇒ b

c ⇒ x

Entonces x=\frac{c*b}{a}

La regla directa de tres es la regla que se aplica en este caso donde hay un cambio de unidades. Para realizar esta conversión de unidades, primero debes saber que 1 km = 3280,84 pies. Entonces, si 1 km son 3280,84 pies, ¿cuántos pies son 12 km?

1 km ⇒ 3280.84 pies

12 km ⇒ x

x=\frac{12 km*3280.84 pies}{1 km}

x= 39370.08 pies

<u><em>La distancia por carretera de Chitré a Parita es de 12 km o 39370.08 pies.</em></u>

7 0
3 years ago
Two blocks joined by a string have masses of 6 and 9 kg. They rest on a frictionless horizontal surface. A 2nd string, attached
Tom [10]

Answer:

12N

Explanation:

Suppose the string mass is negligible, the total mass of the 2 block system is 6 + 9 = 15 kg

So the acceleration of the system when subjected to 30N force is

a = F / M = 30 / 15 = 2 m/s2

So both blocks would have the same acceleration, however, the force acting on the 6kg block would have a magnitude of

f = am = 2 * 6 = 12N

This is the tension in the string between the blocks

5 0
3 years ago
Two long wires hang vertically. Wire 1 carries an upward current of 1.50 A . Wire 2,20.0cm to the right of wire 1, carries a dow
Inessa [10]

The magnitude of the current in wire 3  is 2.4 A and in a direction pointing in the downward direction.

  • The force per unit length between two parallel thin current-carrying I_1 and I_2  wires at distance ' r ' is given by  f=\frac{u_0I_1I_2}{2\pi r}   ....(1) .
  • If the current is flowing in both wires in the same direction, and  the force between them will be the attractive force and if the current is flowing in opposite direction in wires then the force between them will be the repulsive force.

A schematic of the information provided in the question can be seen in the image attached below.

From the image, force on wire 2 due to wire 1 = force on wire 2 due to wire 3

F_2_1=F_2_3

Using equation (1) , we get

\frac{u_0I_2I_1}{0.2} =\frac{u_0I_2I_3}{0.32} \\\\\frac{I_1}{0.2} =\frac{I_3}{0.32} \\\\\frac{1.50}{0.2} =\frac{I_3}{0.32} \\\\0.48=0.2I_3\\\\I_3=2.4A

I₃ = 2.4 A and the current is pointing in the downward direction

Learn more about the magnitude and direction of forces here:

brainly.com/question/14879801?referrer=searchResults

#SPJ4

5 0
1 year ago
The law of conservation of mass applies to all chemical reactions.
serious [3.7K]
True. No matter can be created nor destroyed in pretty much every aspect of life, especially chemical reactions.
3 0
3 years ago
The particles of a substance stay close together but slide past one another as they move when thermal energy is added to the sub
Katen [24]

Answer: A liquid to gas

Explanation: I just got it wrong :(

6 0
3 years ago
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