A ball is thrown into the air with a velocity of 39 ft/s. Its height, in feet, after t seconds is given by s(t) = 39t − 16t2. Find the velocity (in ft/s) of the ball at time t = 1 second.

Answer:

See explanation below

Explanation:

The length of the arrow represents the magnitude/size of the force. The longer it is, the higher the force's magnitude is.

Answer:

30 kilometers is a reasonable measurement

Answer:

The time of flight is [tex]T = \frac{2 u sin A}{g}[/tex].

Explanation:

Let the initial velocity is u and the angle of projection is A.

Use first equation of motion for vertical motion

Let the time to reach the maximum height is t.

[tex]v = u - gt\\\\0 = u sin A - gt \\\\t = \frac{ u sin A}{g}[/tex]

Total time of flight is

T =2  t

[tex]T = \frac{2 u sin A}{g}[/tex]

Answer:

a. 273 K b. 90.1 K c. 5.26 atm d. 0.33 atm

Explanation:

For isothermal expansion PV = constant

So, P₁V₁ = P₂V₂ where P₁ = initial pressure of gas = 1 atm (standard pressure), V₁ = initial volume of gas, P₂ = final pressure of gas and V₂ = final volume of gas,

So, P₁V₁ = P₂V₂

P₂ = P₁V₁/V₂

Since V₂/V₁ = 0.19,

P₂ = P₁V₁/V₂

P₂ = 1 atm (1/0.19)  

P₂ = 5.26 atm

For an adiabatic expansion, PVⁿ = constant where n = ratio of molar heat capacities = 5/3 for monoatomic gas

So, P₂V₂ⁿ = P₃V₃ⁿ where P₂ = initial pressure of gas = 5.26 atm, V₂ = initial volume of gas, P₃ = final pressure of gas and V₃ = final volume of gas,

So, P₂V₂ⁿ = P₃V₃ⁿ

P₃ = P₂V₂ⁿ/V₃ⁿ

P₃ = P₂(V₂/V₃)ⁿ

Since V₃ = V₁ ,V₂/V₃ = V₂/V₁ = 0.19

1/0.19,

P₃ = P₂(V₂/V₃)ⁿ

P₃ = 5.26 atm (0.19)⁽⁵/³⁾

P₃ = 5.26 atm × 0.0628

P₃ = 0.33 atm

Using the ideal gas equation

P₃V₃/T₃ = P₄V₄/T₄ where P₃ = pressure after adiabatic expansion = 0.33 atm , V₃ = volume after adiabatic expansion, T₃ = temperature after adiabatic expansion  P₄ = initial pressure of gas = P₁ = 1 atm , V₄ = initial volume of gas = V₁ and T₄ = initial temperature of gas = T₁ = 273 K (standard temperature)

P₃V₃/T₃ = P₄V₄/T₄

T₃ = P₃V₃T₄/P₄V₄    

T₃ = (P₃/P₄)(V₃/V₄)T₂

Since V₃ = V₄ = V₁ and P₄ = P₁

V₃/V₄ = 1 and P₃/P₄ = P₃/P₁

T₃ = (P₃/P₁)(V₃/V₄)T₂

T₃ = (0.33 atm/1 atm)(1)273 K  

T₃ = 90.1 K

So,

a. The highest temperature attained by the gas is T₁ = 273 K

b. The lowest temperature attained by the gas = T₃ = 90.1 K

c. The highest pressure attained by the gas is P₂ = 5.26 atm

d. The lowest pressure attained by the gas is P₃ = 0.33 atm

Answer:

The speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.

Explanation:

We can calculate the speed of the train using the Doppler equation:

[tex] f = f_{0}\frac{v + v_{o}}{v - v_{s}} [/tex]        

Where:

f₀: is the emitted frequency

f: is the frequency heard by the observer  

v: is the speed of the sound = 343 m/s

[tex] v_{o}[/tex]: is the speed of the observer = 0 (it is heard in the town)

[tex] v_{s}[/tex]: is the speed of the source =?

The frequency of the train before slowing down is given by:

[tex] f_{b} = f_{0}\frac{v}{v - v_{s_{b}}} [/tex]  (1)                  

Now, the frequency of the train after slowing down is:

[tex] f_{a} = f_{0}\frac{v}{v - v_{s_{a}}} [/tex]   (2)  

Dividing equation (1) by (2) we have:

[tex] \frac{f_{b}}{f_{a}} = \frac{f_{0}\frac{v}{v - v_{s_{b}}}}{f_{0}\frac{v}{v - v_{s_{a}}}} [/tex]

[tex] \frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - v_{s_{b}}} [/tex]   (3)  

Also, we know that the speed of the train when it is slowing down is half the initial speed so:

[tex] v_{s_{b}} = 2v_{s_{a}} [/tex]     (4)

Now, by entering equation (4) into (3) we have:

[tex] \frac{f_{b}}{f_{a}} = \frac{v - v_{s_{a}}}{v - 2v_{s_{a}}} [/tex]  

[tex] \frac{300 Hz}{290 Hz} = \frac{343 m/s - v_{s_{a}}}{343 m/s - 2v_{s_{a}}} [/tex]

By solving the above equation for [tex]v_{s_{a}}[/tex] we can find the speed of the train after slowing down:

[tex] v_{s_{a}} = 11.06 m/s [/tex]

Finally, the speed of the train before slowing down is:

[tex] v_{s_{b}} = 11.06 m/s*2 = 22.12 m/s [/tex]

Therefore, the speed of the train before and after slowing down is 22.12 m/s and 11.06 m/s, respectively.                        

I hope it helps you!                                                        

Answer:

The electric field in the center is  [tex]\frac{2k}{\pi R^{2}}\left ( Q_{2}-Q_{1 } \right )[/tex].

Explanation:

Answer:

Mass of car's engine = 342.85 kg (Approx.)

Explanation:

Given values:

Force applied by car = 1,200 N

Acceleration of car' engine = 3.5 m/s²

Find:

Mass of car's engine

Computation:

⇒ Mass = Force / Acceleration

⇒ Mass of car's engine = Force applied by car / Acceleration of car

⇒ Mass of car's engine = 1,200 / 3.5

⇒ Mass of car's engine = 342.85 kg (Approx.)

Answer:

the law of conservation of energy.

Explanation:

An electric circuit can be defined as an interconnection of electrical components which creates a path for the flow of electric charge (electrons) due to a driving voltage.

Generally, an electric circuit consists of electrical components such as resistors, capacitors, battery, transistors, switches, inductors, etc.

In Physics, a point where at least three circuit paths (wires) meet is referred to as a junction.

The Kirchhoff’s circuit laws are two(2) equations first published by Gustav Kirchhoff in 1845.

Fundamentally, they address the conservation of energy and charge in the context of electrical circuits.

One of the laws known as Kirchoff's Current Law (KCL) deals with the principle of application of conserved energy in electrical circuits.

Kirchoff's Current Law (KCL) states that the sum of all currents entering a junction must equal the sum of all currents leaving the junction.

This simply means that the algebraic sum of currents in a network of conductors(wires) meeting at a point is equal to zero.

The Law of Conservation of Energy states that energy cannot be destroyed but can only be transformed or converted from one form to another.

This ultimately implies that, Kirchhoff's junction rule is a statement of the law of conservation of energy.

Answer:

The water usually rushes back too enthusiastically, causing a splash – and the bigger the rock, the bigger the splash. The splash then creates even more ripples that tend to move away from where the rock went into the water.

Answer:

40479.6 J

Explanation:

Applying,

q = cm(t₂-t₁).................... Equation 1

Where q = change in heat content of the system, c = specific heat capacity of the system, m = mass of the system, t₁ = initial temperature, t₂ = final temperature.

From the question,

Given: m = 79 g = 0.079 kg, t₁ = 21°C, t₂ = 143°C

Constant: c = 4200 J/kg.°C

Substitute these values into equation 1

q = 4200(0.079)(143-21)

q = 331.8(122)

q = 40479.6 J

Answer:

the answer is b. reflective

Explanation:

the answer is in the above image

(a) The maximum voltage V is  190 Volts.

(b) The rms voltage V is 95√2 Volts.

(c) The rms current in Amperes is  7.9 A.

(d) The peak current Amperes is  11.18 A.

(e)The current when t = 0.0045 s is 7.26 A.

The current is the stream of charges which flow inside the conductors when connected across the end of voltage.

Given is an AC source is connected across a 17.0 Ω resistor, the output voltage is given by Δv = (190 V)sin(50πt).

(a) From the given voltage equation, maximum voltage V is 190 Volts.

(b) rms voltage =Vmax/√2

Put the values, we get

Vrms = 190/√2 = 95√2 Volts

(c) rms current = Vrms/Resistance

Put the values, we get

Irms =  95√2 /17

Irms = 7.9 Amperes.

(d) peak current  =√2 Irms

Substitute the values, we get

Peak current = 7.9 √2 = 11.18 A

(e) The current when t = 0.0045 s is written as

I =  (190 V)sin(50πt)/R

Substitute the values, we have

I =  (190 )sin(50π x0.0045)/17

I = 7.26 A.

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Answer:

Explanation:

1.00kg×20m/s×cos40=15.3

Answer:

The right solution is "24.39 per sec".

Explanation:

According to the question,

⇒ [tex]v=\frac{502.1}{\sqrt{3} }[/tex]

      [tex]=289.9 \ m/s[/tex]

The time will be:

⇒ [tex]t=\frac{d}{v}[/tex]

      [tex]=\frac{2\times 6}{289.9}[/tex]

      [tex]=\frac{12}{289.9}[/tex]

      [tex]=0.041 \ sec[/tex]

hence,

⇒ [tex]N=\frac{1}{t}[/tex]

        [tex]=\frac{1}{0.041}[/tex]

        [tex]=24.39 \ per \ sec[/tex]

Answer:

[tex]F=5(240t^2i+72tj)\ N[/tex]

Explanation:

Given that,

The mass of the object, m = 5 kg

The position vector is, [tex]r=20t^4i+12t^3j[/tex]

Velocity, [tex]v=\dfrac{dr}{dt}=80t^3i+36t^2j[/tex]

Acceleration, [tex]a=\dfrac{dv}{dt}=240t^2i+72tj[/tex]

Newton's second law of motion is given as follows:

F = ma

Put all the values,

[tex]F=5(240t^2i+72tj)\ N[/tex]

Hence, this is the required solution.

Answer: hello some data related to your question is missing attached below is the missing data and diagram related to the solution

answer:

P = 141.21 N

Explanation:

Given data:

Mass of crate = 50 kg

coefficient  of static friction ( μ ) = 0.25

Calculate minimum horizontal force ( P ) that holds the crate from sliding

∑fx = 0

     = P + Fcos θ - N*sinθ = 0

     = P + 0.25N cos 30° - Nsin30°  = 0

∴ P = 0.2835 N = 0

P - 0.2853 N = 0 ------- ( 1 )

∑fy = 0

     - 50g + Ncosθ + Fsinθ

     - 50*9.81 + Ncos30° + 0.25Nsin30°

∴ N = 494.942 N ----- ( 2 )

input 2 into 1

P - 0.2853 ( 494.942 ) = 0

P = 141.21 N

Answer:

Rahul's weight

Explanation:

In fact, the force Rahul exerts on Earth corresponds to the force of gravity. But Rahul's weight is, in fact, the force of gravity exerted by the Earth on Rahul, and these two forces correspond to the action-reaction pair of Newton's third law, which states that the two forces are equal.

Using formulas, Rahul's weight is equal to

W=mg

where m is Rahul mass and g is the gravitational acceleration (g=9.81 m/s^2).

Answer:

0.444atm

Explanation:

Using the combined gas law equation;

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressure (

P2 = final pressure (

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

According to this question,

P1 = 101.3 kPa = 101.3 × 0.00987 = 0.999atm

P2 = ?

V1 = 80L

V2 = 160L (double of V1)

T1 = 34°C = 34 + 273 = 307K

T2 = 0°C = 0 + 273 = 273K

Using P1V1/T1 = P2V2/T2

0.999 × 80/307 = P2 × 160/273

79.92/307 = 160P2/273

Cross multiply

307 × 160P2 = 79.92 × 273

49120P2 = 21818.16

P2 = 21818.16 ÷ 49120

P2 = 0.444

P2 = 0.444atm

This is the solution of the problem. The problem is calculated from a closed system energy balance equation

Answer:

Explanation:

Of course because it's Newton's Law that if body A exerts force on body B, then body B will exert equal but opposite force on body A.

HAPPY LEARNING:)

The first charged object is exerting a force on the second charged object. The second charged object necessarily exerting a force on the first is correct.

A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

Newton's third law states that for every action (force) in nature there is an equal and opposite reaction, from that we can understand when force is exerted on first charged object is exerting a force on the second charged object. The second charged object necessarily exerting a force on the first.

The first charged object is exerting a force on the second charged object. The second charged object necessarily exerting a force on the first is correct.

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Answer:

a) RADIATION, b) CONVECTION, c)  CONDUCTION, d) CONVECTION

Explanation:

In the heating processes there can be three types: conduction, convention and radiation.

The conduction process occurs when the movement of atoms or thermal agitation of molecules creates the transfer of thermal energy.

The convention process occurs when there is a movement of matter creating the transfer of energy

The process of Radiation an electromagnetic wave indexes on a material and is absorbed, creating the process of energy transfer.

Now let's examine each situation>

a)Warming of the Earth's surface on a sunny day

in this case the sunlight heats the earth as it is absorbed, which is why it is a RADIATION process

b) On a sunny afternoon, you watch cumulus clouds forming

in this case the nines rise from the surface, since it is a moving mass, the process is CONVECTION

c) A very shallow layer of air in contact with the ground is warmed

in this case the thermal movement of the layer molecules heat the earth, for which the process of CONDUCTION

d) A south wind carries warm air into the central United States

As we have a movement of a mass of matter, the process is CONVECTION.

Answer:

12+2=24+30+2=66

Explanation:

Answer:

Explanation:wave=wavelength×frequency,

Answer:

a) True

Explanation:

A program-specific message provided to an individual or group with the intention of raising awareness of a health condition, motivating behavior change, removing perceived barriers to participating in a health habit, or something else relating to the program's aims and objectives. The most effective intervention messages are usually theory-based and culturally adapted.

Answer:

We use a spring of large spring constant.

Explanation:

The spring constant is defined as the force applied on the spring per unit extension or compression in length.

F = k x

where, F is the force, x is the extension, k is the spring constant.

Its unit is N/m.

To get the comfortable ride, we use the spring of large spring constant, so that the spring gets stiffer and we get comfort.

Answer:

Gravitational potential energy is mass of the object times the gravitational constant times the height of the object:

U = mgh (I will use 10 for the gravitational constant but you can use 9.8 or 9.81 or something even more accurate)

U = 280

The gravitational potential of the object is 280 joules