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2 years ago

A brick is resting on a rough incline as shown in the figure. The friction force acting on the brick, along the incline, is

Physics

2 answers:

Tasya [4]2 years ago

6 0

B) equal to the gravitational force of the brick

lakkis [162]2 years ago

4 0

Answer:

D) less than the gravitational force of the brick.

Explanation:

When a brick is at rest on the inclined plane

then we will have all forces balanced on the brick

so we will have force balance along the inclined plane given as

$F_g sin\theta = F_f$

$mg sin\theta = F_f$

on the other side we can find force balance perpendicular to the inclined plane

$mg cos\theta = F_n$

so from above equation we can say that friction force is the component of the weight of the object along the inclined plane

so correct answer is

D) less than the gravitational force of the brick.

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Two separate but nearby coils are mounted along the same axis. A power supply controls the flow of current in the first coil, an

gulaghasi [49]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The correct answer is option c

Explanation:

Faraday states that when there is a change in magnetic field of a coil of a wire, it means that there exist an emf in the circuit which in induced due to the change in the magnetic flux

From the question two separate but nearby coils are mounted along the axis. First coil is connected to the power supply and the current flow is controlled by the supply.When the current alternates, it would produce magnetic field ,also the second coil is connected to an ammeter which indicates the current that is flowing in it when current in the first coil changes

This magnetic field that is produce would cause a change flux which would induce current in the second coil so the ammeter would indicate current flow in the second coil

a is incorrect because the current in fir coil is not change hence flux won't change therefore current is is not induced in second coil

This is the same reason b is incorrect

d is incorrect due to the fact that when the second coil is connected to a power supply by rewiring it to be in series with first coil the law of electromagnetism would no longer hold so he ammeter would show no reading

6 0

2 years ago

before colliding, the momentum of block A is +15.0 kg m/s. after, block A has a momentum -12.0 kg*m/s. what is the momentum of b

Helen [10]

Answer:

The momentum of block B = 27 Kg m/s

Explanation:

Given,

The initial momentum of block A, MU = 15 Kg m/s

The final momentum of block A, MV = -12 Kg m/s

Consider the block B is initially at rest.

Therefore, the initial momentum of block B, mu = 0

According to the laws of conservation of linear momentum, the momentum of the body before impact is equal to the momentum of the body after impact.

15 + (0) = (-12) + mv

mv = 15 + 12

= 27 Kg m/s

Hence, the momentum of the block B after impact is, mv = 27 Kg m/s

3 0

2 years ago

un tanque de gasolina de 40 litros fue llenado por la noche, cuando la temperatura era de 68 grados farenheit. Al dia siguiente

Sedaia [141]

Answer:

Volume of gasoline that expands and spills out is 1.33 ltr

Explanation:

As we know that when temperature of the liquid is increased then its volume will expand and it is given as

$\Delta V = V_o\gamma \Delta T$

here we know that

$V_o = 40 Ltr$

volume expansion coefficient of the gasoline is given as

$\gamma = 950 × 10^{–6}$

change in temperature is given as

$\Delta T = (131 - 68) \times \frac{5}{9}$

$\Delta T = 35 ^oC$

Now we have

$\Delta V = 40(950 \times 10^{-6})(35)$

$\Delta V = 1.33 Ltr$

3 0

2 years ago

A circular pipe of 25-mm outside diameter is placed in an airstream at 25C and 1-atm pressure. The air moves in cross flow over

kifflom [539]

Answer:

f_D = =3.24 N/m

Explanation:

data given

properties of air $\nu\ of air =19.31*10^{-6} m2/s$

$\rho = 1.048 kg/m3$

k = 0.0288 W/m.K

WE KNOW THAT

Reynold's number is given as

$Re =\frac{VD}{\nu}$

$= \frac{ 15*0.025}{19.31*10^{-6}}$

= 1.941 *10^4

drag coffecient is given as

$C_D = \frac{f_D}{A_f\frac{\rho v^2}{2}}$

solving for f_D

$f_D = C_D A_f*\frac{\rho v^2}{2}$

$=C_D D*\frac{\rho v^2}{2}$

Drag coffecient for smooth circular cylinder is 1.1

therefore Drag force is

$f_D = 1.1*0.025 *\frac{1.048*15^2}{2}$

f_D = =3.24 N/m

4 0

2 years ago

A new class of objects can be created conveniently by ________; the new class (called the ________) starts with the characterist

iVinArrow [24]

Answer:

Option A is correct.

Inheritance, superclass, subclass

A new class of objects can be created conveniently by **inheritance**; the new class (called the **superclass**) starts with the characteristics of an existing class (called the **subclass**), possibly customizing them and adding unique characteristics of its own.

Explanation:

A class is a term in object oriented programming that is extensible program code used to create, name and implement what you want the objects to do.

Inheritance is used to describe the making of new classes from already existing classes. The general properties of the old classes remain in the new classes created from them.

Hence, the new classes (because they're usually an improvement on the old classes as they hold on to the wanted properties of the old classes and additional great ones are added or modified) are called superclasses and the old, already existing ones are called subclasses.

3 0

2 years ago