A gas is enclosed in a confainer fitted with a piston of cross sectional area 0.10 the pressureof the gas is maintained in 8000 when hat is slowlh transferred the piston is pushed up through a distance of 4.0cm If 42j of heat is transferred to the system during expansion wht is the change im internal energy of th system

Answer:

This question is incomplete but the completed question is below

As a girl pushes an object across a wood floor, she suddenly comes to an area where the floor has been waxed recently, making it slippery. What becomes true of the coefficient of kinetic friction? A. The coefficient of kinetic friction increases. B. The coefficient of kinetic friction decreases. C. The coefficient of kinetic friction becomes zero. D. The coefficient of kinetic friction becomes negative.

The correct option is B

Explanation:

Coefficient of kinetic friction can be defined as the frictional force resisted by the motion of an object. From the question, it might take the girl to apply a force equivalent to just half that of the weight of the object to overcome friction to keep the object moving on a wood floor. Once she gets to the waxed area, the frictional force reduces, thereby also reducing the coefficient of kinetic friction further. Thus, she will be able to use less than half of the force (equivalent to less than half of the weight of the object) to push the object.

Thus, the correct option is B.

Answer:

(a) i) The distance travelled by the cycle in half round is approximately 65.97 m

ii) The displacement is 42 m

(b) (i) The distance travelled in one round is approximately 131.95 m

(ii) The displacement of the cycle in one round is 0

Explanation:

The diameter of the track through which the cycle travels, D = 42 m

(a) i) Half round is the motion of half the length of the circular path

The distance travelled by the cycle in half round = The length of half the circular track = (1/2) × π × D

∴ The distance travelled by the cycle in half round = (1/2) × π × 42 m = 21·π m ≈ 65.97 m

ii) The displacement half round = The change in the location of the cycle = The difference between the start and stop locations of the cycle on a straight line after half round

The angle at the center of the circular path the cycle turns in half round  = 180°

Therefore, the path between the start and stop location of the cycle in half round = The diameter of the circular track

The displacement of the cycle in half round = The diameter of the circular track = 42 m

(b) (i) The distance travelled in one round = The perimeter of the circular track = π·D

∴ The distance travelled in one round = π × 42 m ≈ 131.95 m

(ii) The displacement of the cycle in one round = The change in the location of the cycle

The start and stop location of the cycle after moving one round is the same, therefore, there is no change in the location of the cycle.

Therefore we have;

The displacement of the cycle in one round = 0 (no change in location of the cycle)

Answer:

Explanation:

mass and distance

Answer:

R = 0.86 m

Explanation:

The formula for the range of the projectile motion can be used here:

[tex]R = \frac{v^2 Sin2\theta}{g}[/tex]

where,

R = Range of projectile = distance between Jake and Fred = ?

v = launch speed = 3 m/s

θ = Launch Angle = 35°

g = acceleration due to gravity = 9.81 m/s²

Therefore,

[tex]R = \frac{(3\ m/s)^2Sin[(2)(35^o)]}{9.81\ m/s^2}\\\\[/tex]

R = 0.86 m

Answer:

Attenuation

Step By step Explanation:

The decrease in the intensity of light over distance, such as with increasing depth in water, is known as ______.

It is called attenuation.

The decraese in the amplitude of the signals is called attenuation.

Explanation:

A diode is an electrical element which offers the flow of current freely in one direction with very less resistance.

The given figure depicts a diode in forward bias, where the p-side and the n-side of the diode are connected to positive and negative terminals respectively. In such a case the current flows from the p-side to n-side of the p-n junction very easily and the value of the current increases rapidly after a certain voltage, this voltage is called threshold voltage.

We can deduce from the graph that the resistance of the diode reduces with increase in voltage. As resistance is given by the formula:

[tex]R=\frac{V}{i}[/tex]

Answer:

The type of image formed on a screen by a convex lens is real, enlarged and inverted.

Explanation:

A lens can be defined as a transparent optical instrument that refracts rays of light to produce a real image.

Basically, there are two (2) main types of lens and these includes;

I. Diverging (concave) lens.

II. Converging (convex) lens.

A converging lens refers to a type of lens that typically causes parallel rays of light with respect to its principal axis to come to a focus (converge) and form a real image.

Basically, the type of image formed on a screen by a converging (convex) lens is real, enlarged and inverted because it is usually thick across the middle (causing rays of light to converge) but thin at the lower and upper edges.

Answer:

[tex]H_{max}=3.4m[/tex]

Explanation:

From the question we are told that:

Mass 1 [tex]m_1=5kg[/tex]

Mass  [tex]m_2=2kg[/tex]

Distance above floor [tex]d=2.5m[/tex]

Generally the equation for Conservation of energy is mathematically given by

[tex]0.5m_1v^2+0.5m_2v^2=2mg[/tex]

[tex]0.5m_1v^2+0.5m_2v^2=2g(m_1-m_2)[/tex]

[tex]v^2(0.5*m_1+0.5*m_2)=2*g(m_1-m_2)[/tex]

[tex]v^2(0.5*5+0.5*2) = 2 * 9.8 * (5 - 2)[/tex]

[tex]v^2=\frac{58.8}{3.5}[/tex]

[tex]v=4.1m/s[/tex]

Generally the equation for The maximum height of lighter block  is mathematically given by

[tex]H_{max}=d+\frac{v^2}{2g}[/tex]

[tex]H_{max}=2.5+\frac{16.2}{2*9.81}[/tex]

[tex]H_{max}=3.4m[/tex]

Answer:

For smooth surface:The light rays bounce off the table and all move in the same direction.

Speed = Distance/Time

=> Speed = 100m/16s

=> Speed = 6.25m/s

=> Speed = 6.25 ms^-1

Explanation:

Given that,

The voltages across them are 40,50 and 60 volts respectively, and the charge on each condenser is 6×10⁻⁸ C.

(a) Capacitance of capacitor 1,

[tex]C_1=\dfrac{Q}{V_1}\\\\C_1=\dfrac{6\times 10^{-8}}{40}\\\\C_1=1.5\times 10^{-9}\ F\\\\C_1=1.5\ nF[/tex]

Capacitance of capacitor 2,

[tex]C_2=\dfrac{Q}{V_2}\\\\C_2=\dfrac{6\times 10^{-8}}{50}\\\\C_2=1.2\times 10^{-9}\ F\\\\C_2=1.2\ nF[/tex]

Capacitance of capacitor 3,

[tex]C_3=\dfrac{Q}{V_3}\\\\C_3=\dfrac{6\times 10^{-8}}{60}\\\\C_3=1\times 10^{-9}\ F\\\\C_3=1\ nF[/tex]

(b) The equivalent capacitance in series combination is :

[tex]\dfrac{1}{C}=\dfrac{1}{C_1}+\dfrac{1}{C_2}+\dfrac{1}{C_3}\\\\\dfrac{1}{C}=\dfrac{1}{1.5}+\dfrac{1}{1.2}+\dfrac{1}{1}\\\\C=0.4\ nF[/tex]

Hence, this is the required solution.

Answer:

Average speed = 24 km/h

Explanation:

Given the following data;

Uniform speed A = 30 km/h

Uniform speed B = 20 km/h

To find the average speed;

Mathematically, the average speed of an object is given by the formula;

[tex] Average \; speed = \frac {total \; distance}{total \; time} [/tex] ..... equation 1

Total time = TA + TB

[tex] T_{A} = \frac {x}{30} [/tex]

[tex] T_{B} = \frac {x}{20} [/tex]

[tex] Total \; time = \frac {x}{30} + \frac {x}{20} [/tex]

[tex] Total \; time = \frac {5x}{60} [/tex]

Total distance = x + x

Total distance = 2x

Substituting the values into equation 1;

[tex] Average \; speed = \frac {2x}{\frac {5x}{60}} [/tex]

[tex] Average \; speed = \frac {2x*60}{5x} [/tex]

[tex] Average \; speed = \frac {120}{5} [/tex]

Average speed = 24 km/h

Answer:

attached below

Explanation:

The initial conditions :

x(0) = - 9 inches = -3/4 ft

x'(0) = - 2 ft/sec

spring stretched  3 inches = 1/4 ft

mass = w / g = 4 Ib / 32 ft/sec^2 = 1/8  slug

the spring constant ( k ) = w / l  = 4 / ( 1/4 ) = 16 Ib/ft

applying the second law of motion

m d^2x/dt^2 +  b dx/dt  + kx

= 1/8 d^2x/dt^2  + 2 dx/dt  + 16 x

= d^2x/dt^2  + 16 dx/dt  +  128 x  ------- ( 1 )

we will resolve the above equation to obtain the required equation of motion  x( t )

Attached below is the remaining part of the solution

Answer:

Explained below.

Explanation:

Let the initial velocity from the top of the tower of height(h) be u'

Now, since it is projected horizontally, the horizontal distance covered will be due to having a uniform horizontal velocity (u) while it will possess a vertical distance in the downward direction due to constant acceleration due to gravity (g).

If the time it takes the ball to reach the ground is "t", then we can say the horizontal distance travelled by the ball is denoted as; x(t) = x, while the vertical distance is denoted by; y(t) = y

Now, since it's a projectile the intial velocity (u) will have vertical and horizontal components which are;

u_y and u_x respectively.

Applying kinematic equations, we have;

x = u_x•t + ½at²

Acceleration is zero in the horizontal x direction. Thus;

x = u_x•t

For the vertical y-direction;

y = u_y•t + ½at²

Here since direction is in that of gravity, then a = g.

Also, since the initial velocity has no downward component, then u_y = 0 m/s

Thus;

y = ½gt²

From x = u_x•t, we have;

t = x/u_x

Thus;

y = ½g(x/u_x)²

y = ½gx²/(u_x)²

Let g/(u_x)² be treated as a constant with the letter k.

Thus;

y = kx²

This is the form of a parabolic equation.

Thus, it has been proved that the projectile follows the path of a parabola.

Answer:

B

Explanation:

The writers are from a trusted source that is considered impartial. The message is backed up by scientific investigation, and the writers have no monetary gain from their message.

Answer:

Value of the resistors​ R = 2 ohm

Explanation:

Given:

Resistor R1 = 4 ohm

Resistor R2 = 4 ohm

Find:

Value of the resistors​ R

Computation:

We know that Resistor R1 and Resistor R2 connected in parallel series.

So,

Using common resistance in parallel series

⇒ 1/R = 1/R1 + 1/R2

⇒ 1/R = 1/4 + 1/4

⇒ 1/R = (1 + 1) / 4

⇒ 1/R = 2/4

⇒ R = 4/2

⇒ R = 2

Value of the resistors​ R = 2 ohm

Answer:

It was proposed by Isaac Newton

Explanation:

The law of universal attraction of expression

          F = [tex]G \ \frac{m_1m_2}{ r^2}[/tex]G m1m2 / r ^ 2

where G is a constant, m₁ and m₂ are the masses of the bodies and r the distance between them.

It was proposed by Isaac Newton

With this law Newton explained that the force that pulls the moon towards the earth is the same as that which attracts an apple towards the earth

the correct answer is ---- 122

Explanation:

the high heels has a more pressure than flat soles bcoz small area has more pressure than large area.

Direct current (DC) is the flow of electric charge in only one direction. It is the steady state of a constant-voltage circuit. Most well-known applications, however, use a time-varying voltage source. Alternating current (AC) is the flow of electric charge that periodically reverses direction.

Answer:

1.the friction of air, gravity2.gravity

Answer:

The softball experiences an applied force as a result of Amy’s throw. As the ball moves, it experiences drag from the air it passes through. It also experiences a downward pull because of gravity.

Explanation:

Plato

Answer:

[tex]d=0.59m[/tex]

Explanation:

From the question we are told that:

Mass [tex]m=67.3 kg[/tex]

Spring constant [tex]\mu=1.23 * 10^3 N/m[/tex]

Fall Height [tex]h=0.921m[/tex]

Generally the Energy theorem equation for momentum is mathematically given by

Change in KE=Work done by gravity + work done by spring

[tex]0=mg*(h + d) - \frac{\mu d^2}{2}[/tex]

[tex]0=(67.3 * 9.81 (0.921 + d)) -\frac{(1.23 * 10^3 * d^2}{ 2}[/tex]

[tex]0=608.1-660.213d-615d^2[/tex]

Solving Quadratic equation

[tex]d=0.59m[/tex]

Answer:

:) :) :) :) :) :) :) :) :)

Explanation:

:) :) :) .......

Answer:

1. 100 J

2. 225 J

Explanation:

We'll begin by calculating the mass of the object. This can be obtained as follow:

Velocity (v) = 5 ms¯¹

Kinetic energy (KE) = 25 J

Mass (m) =?

KE = ½mv²

25 = ½ × m × 5²

25 = ½ × m × 25

25 = 25m / 2

Cross multiply

25m = 25 × 2

25m = 50

Divide both side by 25

m = 50 / 25

m = 2 Kg

1. Determination of the kinetic energy when the velocity is doubled.

Mass (m) = 2 Kg

Velocity (v) = double the initial velocity

= 2 × 5 ms¯¹

= 10 ms¯¹

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 2 × 10²

KE = ½ × 2 × 100

KE = 100 J

2. Determination of the kinetic energy when the velocity increased three times.

Mass (m) = 2 Kg

Velocity (v) = three times the initial velocity

= 3 × 5 ms¯¹

= 15 ms¯¹

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 2 × 15²

KE = ½ × 2 × 225

KE = 225 J

Answer:

Option D. 5Ω e 0.6 A

Explanation:

1. Determination of the equivalent resistance.

We'll begin by calculating the equivalent resistance of resistor B and resistor C. This can be obtained as follow:

Resistor B (R₆) = 2 Ω

Resistor C (R꜀) = 2 Ω

Equivalent Resistance (R₆꜀) =?

R₆꜀ = R₆ × R꜀ / R₆ + R꜀ (parallel connection)

R₆꜀ = 2 × 2 / 2 + 2

R₆꜀ = 4 / 4

R₆꜀ = 1 Ω

Finally, we shall determine the equivalent resistance of the circuit. This can be obtained as follow:

Resistor A (Rₐ) = 2 Ω

Equivalent resistance of resistor B and C (R₆꜀) = 1 Ω

Resistor D (Rₔ) = 2 Ω

Equivalent Resistance (R) =?

R = Rₐ + R₆꜀ + Rₔ (series connection)

R = 2 + 1 + 2

R = 5 Ω

Thus, the equivalent resistance of the circuit is 5 Ω

2. Determination of the total current in the circuit.

Potential difference (V) = 3 V

Equivalent resistance (R) = 5 Ω

Total current (I) =?

V = IR

3 = I × 5

Divide both side by 5

I = 3 / 5

I = 0.6 A

Thus, the total current in the circuit is 0.6 A

Summary:

Equivalent resistance = 5 Ω

Current = 0.6 A

Option D gives the current answer to the question.