A truck is moving with a certain uniform velocity. It is accelerated uniformly by 0.75 m/s^2. After 20 seconds , the velocity becomes 72km/h.Find the initial velocity

Answer:

car is moving away its direction is negative.

the speed must also be negative.

speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.

Explanation:

In the exercise they indicate that the direction to the motion sensor is positive, as they indicate that the car is moving away its direction is negative.

The speed of the car is

           v = (x₂-x₁) / t

As the positions are negative, and the car moves away the speed must also be negative.

The analysis for acceleration must be very careful if the speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.

Answer:

900 cm/s or 9 m/s.

Explanation:

Data obtained from the question include the following:

Length (L) = 30 cm

frequency (f) = 60 Hz

Velocity (v) =.?

Next, we shall determine the wavelength (λ).

This is illustrated below:

Since the wave have 4 node, the wavelength of the wave will be:

λ = 2L/4

Length (L) = 30 cm

wavelength (λ) =.?

λ = 2L/4

λ = 2×30/4

λ = 60/4

λ = 15 cm

Therefore, the wavelength (λ) is 15 cm

Now, we can obtain the speed of the wave as follow:

wavelength (λ) = 15 cm

frequency (f) = 60 Hz

Velocity (v) =.?

v = λf

v = 15 × 60

v = 900 cm/s

Thus, converting 900 cm/s to m/s

We have:

100 cm/s = 1 m/s

900 cm/s = 900/100 = 9 m/s

Therefore, the speed of the wave is 900 cm/s or 9 m/s.

Answer:

B. they have less mass than their reactants

Explanation:

In both nuclear fission and nuclear fusion, the products have less mass than their reactants. So, option B is correct.

Nuclear reaction is defined as the reaction that involves the collision between one or more atomic nuclei and a highly energetic subatomic particle to produce one or more nuclei along with the emission of a large amount of energy.

Here,

Nuclear fission and fusion are two types of nuclear reactions that involves the production of large amount of energy from atomic nuclei.

Nuclear fission is the nuclear reaction in which a heavier nucleus is split into two or more lighter nuclei, under radioactive condition, with the release of a massive amount of energy.

Nuclear fusion is the nuclear reaction in which two or more lighter nuclei nuclei fuse together under radioactive condition and forms a heavier nuclei and by releasing a large amount of energy.

In both nuclear fission and nuclear fusion, there occurs a release of large amount of energy. This is because most of the mass of the reactants is converted into energy which is known as the mass-energy. So the products of these nuclear reactions will have lesser mass than their reactants.

Hence,

In both nuclear fission and nuclear fusion, the products have less mass than their reactants.

To learn more about nuclear reactions, click:

https://brainly.com/question/12786977

#SPJ3

Answer:

The magnitude and direction of the force per unit length of one wire on the other is 2 x 10⁻⁵ N/m, attractive force.

Explanation:

Given;

distance between the two parallel wires, r = 10 cm = 0.1 m

current in the first wire, I₁ = 2A

current in the second wire, I₂ = 5 A

The force per unit length on each wire can be calculated as;

[tex]\frac{F}{L} = \frac{\mu_oI_1I_2}{2\pi r}[/tex]

where;

μ₀ is permeability of free space = 4π x 10⁻⁷ m/A

[tex]\frac{F}{L} = \frac{\mu_oI_1I_2}{2\pi r} \\\\\frac{F}{L} = \frac{4\pi*10^{-7}*2*5}{2\pi *0.1} \\\\\frac{F}{L} = 2 *10^{-5} \ N[/tex]/ m

The direction of the force between the two wires is attractive since the current in the two wires are in opposite direction.

Therefore, the magnitude and direction of the force per unit length of one wire on the other is 2 x 10⁻⁵ N/m, attractive force.

Answer:

Explanation:

the resistance of a electrical device

R = V² / P where V is volt and P is power .

The devices are in parallel so same volt will apply on them

So R₁ = 12² / 32.5 = 4.431 ohm

R₂ = 12² / 2 x 10³ = .072 ohm

when they are in series

Common Current in them = 12 / 4.431 + .072

= 2.6649 A

power consumed by first device when they are in series

= current² x resistance

= 2.6649² x 4.431 = 31.46 W

power consumed by other

= 2.6649² x .072  = .511 W

Answer:

yeah this statement is tru

Explanation:

it is because the speed of the bullet is more than the speed of rolling ball .so from this reason we cannot catch a bullet.

A bullet will be moving much faster than a rolling ball. Even seeing a bullet in flight requires it to be extremely low velocity.

Answer:

Sa is the salary of the governor of state A

Sb  is the salary of the governor of state A

"The governor of state A earns $53,745 more than the governor of state B. "

This means that:

Sa = Sb + $53,745

"If the total of their salaries is $289,405,"

means that:

Sa + Sb = $289,405

Then we have two equations:

Sa = Sb + $53,745

Sa + Sb = $289,405

Now, we can replace the first equation into the second equation:

(Sb + $53,745) + Sb = $289,405

2*Sb = $289,405 - $53,745 = $235,660

Sb = ($235,660)/2 = $117,830

and:

Sa = Sb +  $53,745 =  $117,830 + $53,745 = $171,575

Governor of state A earns:  $171,575

Governor of state B earns:  $117,830

Answer:

2 hrs

Explanation:

time = distance ÷ speed

Answer:

[tex]E=6.01\times 10^{-3}\ J[/tex]

Explanation:

It is given that,

Side of a square loop, l = 24 cm = 0.24 m

Resistance of loop, R = 6.1 ohms

Initial magnetic field is 0.665 T and final magnetic field is 0 as the field is removed in 40 ms

We need to find the electrical energy dissipated in this process.

Due to change in magnetic field, the loop will induce a voltage. The induced voltage is given by :

[tex]V=-\dfrac{dB}{dt}\\\\V=\dfrac{BA}{t}[/tex]

If I is induced current then,

[tex]V=IR[/tex]

[tex]I=\dfrac{V}{R}\\\\I=\dfrac{BA}{tR}[/tex]

Power is given by voltage times current. So,

[tex]P=\dfrac{(BA)^2}{(t^2R)}[/tex]

Now, energy is given by the product of power and time. So,

[tex]E=\dfrac{(BA)^2}{(t^2R)}\times t\\\\E=\dfrac{(BA)^2}{(tR)}[/tex]

Now putting all the values in above formula. So,

[tex]E=\dfrac{(0.665\times (0.24)^2)^2}{(40\times 10^{-3}\times 6.1)}\\\\E=6.01\times 10^{-3}\ J[/tex]

So, the electrical energy of [tex]6.01\times 10^{-3}\ J[/tex] is dissipated in this process.

The electrical energy dissipated throughout this process will be "6.01 × 10⁻³ J".

According to the question,

Square loop's side, l = 24 cm or,

                                  = 0.24 m

Loop's resistance, R = 6.1 ohms

Initial magnetic field = 0.665 T

Final magnetic field = 0

We know the relation,

→ V = - [tex]\frac{dB}{dt}[/tex]

      = [tex]\frac{BA}{t}[/tex]

Also we know,

Current, V = IR

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

                 = [tex]\frac{BA}{tR}[/tex]

Now, Energy, E = [tex]\frac{(BA)^2}{t^2R}[/tex] × t or,

                          = [tex]\frac{(BA)^2}{tR}[/tex]

By substituting the values,

                          = [tex]\frac{(0.665\times (0.24)^2)^2}{40\times 10^{-3}\times 6.1}[/tex]

                          = 6.01 × 10⁻³ J

Thus the response above is correct.                                  

Find out more information about magnetic field here:

https://brainly.com/question/26257705

Answer:

1.25x10^-19N

Explanation:see attached file pls

Explanation:

Given,

I = 5 A

V = 240 V

T = 25 mins = 1500 sec

Now,

Energy dissipated = IVT= 5×240×1500 = 1800000 J

Answer:

[tex]D.\ 970\ N[/tex]

Explanation:

Given:

Mass of Piano: 99kg

Required:

Calculate its weight

The weight of an object is calculate as thus;

[tex]Weight = Mass\ (m) * Acceleration\ due\ to\ gravity\ (g)[/tex]

[tex]m = 99kg[/tex] and [tex]g = 9.8m/s^2[/tex]

The formula becomes

[tex]Weight = 99kg * 9.8m/s^2[/tex]

[tex]Weight = 970.2\ kgm/s^2[/tex]

[tex]Weight = 970.2\ N[/tex]

[tex]Weight = 970\ N[/tex] Approximated

Hence, the weight of the piano is 970N

Answer:

A.) Find the attached file

B.) 1.536 J

C.) 123N

Explanation:

Given that the force (F) in Newtons, of his breath as a function of the distance along the straw (x) in meters, can be modeled as a linearly decreasing function for the first half of the straw,

Half of the straw = 12.5 cm

Let Force F = dependent variable

And distance x = independent variable

A.) Find the attached file for the graph.

Sinnce the force decreases by half along the first half of the straw. Assume there is negligible friction and the straw is held horizontally

B.) Given that the mass M = 12g = 12/1000 = 0.012kg

And Velocity V = 16m/s

The workdone = the kinetic energy of the split ball

WD = 1/2mv^2

Substitutes m and V into the formula

WD = 1/2 × 0.012 × 16^2

WD = 1.536 Joule

C.) The maximum force acts on the spit ball will be at maximum kinetic energy.

Since work done = force × distance

Where distance = 12.5 cm

F × S = 1/2mv^2

Substitutes all the parameters

F × 0.0125 = 1.536

Make F the subject of formula

F = 1.536/0.0125

F = 122.88 N

The maximum force F0, that acts on the spitball is therefore equal to 123 N approximately.

We have that for the Question "(a) Sketch a plot of the force of his breath as a function of position along the straw, labeling the force at x = 0 as F0.

(b) If the spitball begins from rest and leaves the straw with a speed of 16 m/s, how much work is done on the spitball?

(c) What is the maximum force F0, that acts on the spitball?"

It can be said that

From the question we are told

mass of spitball = 12g through a 25.0 cm straw

Generally the equation for workdone is mathematically given as

[tex]= \frac{1}{2}mv^2 - 0\\\\= \frac{1}{2} * 12*10^{-3} * 16^2\\\\= 1.536J[/tex]

Maximum force

[tex]w = \frac{1}{2}*\frac{x_0}{2}*\frac{F_0}{2} + x_0*\frac{F_0}{2}\\\\w = \frac{5}{8}x_0F_0[/tex]

Therefore,

[tex]F_0 = \frac{8w}{5x_0}\\\\F_0 = \frac{8*1.536}{5*25*10^[-2]}\\\\F_0 = 6.4N[/tex]

For more information on this visit

https://brainly.com/question/23379286

Answer:

(a) Error: Other's ; Correction: Others'

(b) Error: to ; Correction: for

(c) Error: with ; Correction: of

(d) Error: prepares ; Correction: prepare

Explanation:

a)  The error is in the word "other's" as the position of apostrophe is wrong, so the correct word will be "others'", it shows plural nouns.

b)  The error is in the word "to", so the correct word will be "for" as for is use to talk about a purpose.

c)  The error is in the word "with"  and the correct word will be "of" as of indicates relationships between other words including things that made of other things.

d)  The error is in the word "preapres" and the correct word will be "prepare".

Answer:

59%

Explanation:

Data obtained from the question include the following:

Input temperature = 495 K

Output temperature = 293 K

Efficiency =?

The efficiency of the car engine can be obtained by multiplying the ratio of the output temperature to the input temperature by 100 as shown below:

Efficiency = output /input x 100

Efficiency = 293/495 x 100

Efficiency = 59.1 ≈ 59%

Therefore, the efficiency of the car engine is approximately 59%

Answer:

According to super hero logic , nothing will happen to him.

But according to science , yes he will get current shock but good news is that he wouldn't get elected until he is in contact with the wires.

He may / may not be affected but his suit will be damaged for sure as it is made of metal.

HOPE THIS HLEP AND PLSSSSS MARK AS BRAINLIEST AND THNXX :)

Answer:

Explanation:

Friction causes generation of heat and causes increased wear and tear.

The friction is a resistive force and is related to heat energy, so an increase in friction results in the generation of heat, so option D is correct.

Two solid objects cannot roll or slide over one another due to the force of friction. Although frictional forces can be useful, such as the traction needed to walk without slipping, they can also present a large degree of resistance to motion. Automobile engines need about 20% of their power to overcome frictional forces in moving parts.

The fundamental source of friction between metals appears to be the adhesion forces between the contact zones of the surfaces, which are always microscopically uneven. Friction is produced by shearing, these "welded" seams, and the rubbing action of the rougher, tougher surface against the softer, smoother surface.

The friction is a resistive force trying to oppose the force applied As friction is related to heat when we increase the heat, the friction increases, and vice versa.

To know more about Friction:

https://brainly.com/question/28356847

#SPJ6

Answer:

1: the refracted angle in the first face is equal to the incident angle that is 60degrees

2. Emergence Angle is 42degrees

Explanation:

Pls see attached file

Answer:

12 Ω

Explanation:

Data obtained from the question include:

Resistor 1 (R1) = 50 Ω.

Resistor 2 (R1) = 30 Ω.

Resistor 3 (R3) = 20 Ω.

Resistor 4 (R4) = R

Galvanometer reading = Zero deflection.

The Resistor 4 (R4) in the Wheatstone bridge can be obtained as follow:

Since the galvanometer gives zero deflection, it means the bridge is balanced. Therefore,

R1/R2 = R3/R4

50/30 = 20/R

Cross multiply

50 x R = 30 x 20

Divide both side by 50

R = (30 x 20)/50

R = 12 Ω

Therefore, the value of R in the wheatstone bridge is 12 Ω.

Answer:

625 cm²

Explanation:

The pressure is the same on both pistons.

F/A = F/A

200 N / 25 cm² = 5000 N / A

A = 625 cm²

Answer:

The relative velocity of an object A with respect to another object B.

Explanation:

The relative velocity of an object A with respect to another object B is the velocity that object A would appear to have to an observer situated on object B moving along with it.

a).  frequency = (speed) / (wavelength)

The speed of light is around 3 x 10⁸ m/s.

For 380 nm (violet light), frequency = (3 x 10⁸ m/s) / (380 x 10⁻⁹ m)

Frequency = 7.89 x 10¹⁴ Hz

For 760 nm (red light), frequency = (3 x 10⁸ m/s) / (760 x 10⁻⁹/s)

Frequency = 3.94 x 10¹⁴ Hz

The ratio is 2 .

That's 1 octave, or 0.3 of a decade.

b).  The ratio of highest/lowest sounds is (20,000 Hz/20 Hz) = 1,000

That's 3 decades, or about 10 octaves.

===> Speaking logarithmically ( ! ), ears are sensitive to a range of sound frequencies that's 10 times as wide as the range of light frequencies that eyes can detect.

Answer:

On heating gases expands than solid and liquid because the molecules gets seperated and the volume increases that causes to expand.

Explanation:

Hope it is helpful

please mark me as brainliest

please

Explanation:

m = kg. v=m/s. g=m/s^2. h= m

>>1/2mv^2=mgh

>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m

>>1/2mv^2=mgh>> kg*(m/s)^2= kg*m/s^2*m>>kg m^2/s^2=kg m^2/s^2 the fraction 1/2 won't be able to make any changes to to the dimensional expression of energy i.e half of energy is still energy therefore you can neglect the number .

>>kg m^2/s^2=kg m^2/s^2

>>J= J

Answer:

He should aim it at the monkey

Explanation:

The question is related to projectile motion of an arrow from a bow such that the arrow is able to reach a specific target

Therefore, since the monkey is going to drop from the tree the instant the person launches the food, then for the monkey to be able reach the food, we have;

Final level position of the launched food should be ≥ The level of the monkey

As the monkey is dropping from the tree the destination of the launched food should be at the monkey so that before the food gets to the position where the monkey was when launching the food with the arrow, the monkey will be slightly lower so as to be able to catch the food or return up the tree to get the food rather than the food falling to the ground.

The amount of lighting on a surface drops to (1/4) of the initial illumination when the distance between a light source and the surface it falls on is doubled.

The amount of light or luminous flux that falls on a surface is known as illumination. It is expressed as lux or lumens per square meter.

The square of the distance has an inverse relationship with the light intensity;

[tex]\rm I = \frac{1}{r^2}[/tex]

Where,

I is the light intensity

r is the distance

Let r is the distance and I is the sound intensity for case 2;

r' = 2r

[tex]\rm I' = \frac{1}{(2r)^2} \\\\ I' = \frac{1}{4r^2} \\\\ I' = \frac{I}{4}[/tex]

When we double the distance between a source of light and the surface on which it falls, the amount of illumination on the surface decreases to(1/2) of the original illumination.

Hence the value of the fraction is 1/4.

To learn more about the illumination refer;

https://brainly.com/question/20160684

#SPJ2

Answer:

Option d = all of the above.

Explanation:

This question is more of a driving lesson or tutorial Question and not that scientific, it is logical and the "rule" attached to reversing and driving that is operating of vehicles especially cars, trucks and so on.

All the options given in the Question from option 'a' to option 'c' are all correct when driving backwards that is reversing or backing . Driving backward(backing or reversing) is not as easy as during forward (drive mode).

=> " Position your right hand on the back of the passenger seat. Grip the steering wheel at the 12 o’clock position with your left hand"

REASON: FOR BALANCING.

=> " Move the wheel left or right in the direction in which you want the rear of the vehicle to go."

The above, given in the Question are all correct.

When backing straight or to the right, all of the mentioned options are correct and recommended practices are to Position your right hand on the back of the passenger seat. The correct option is option d.

a) Position your right hand on the back of the passenger seat: This is a technique used by some drivers to help them have a better sense of the vehicle's position and reference point while backing up.

b) Grip the steering wheel at the 12 o'clock position with your left hand: This hand position allows for better control and maneuverability of the steering wheel while backing up.

c) Move the wheel left or right in the direction in which you want the rear of the vehicle to go: This is the fundamental principle of steering while backing up. By turning the wheel in the desired direction, you can guide the rear of the vehicle in that direction.

Therefore, These practices can assist in improving control, visibility, and maneuverability while backing up, ensuring a safer and more effective backing maneuver. The correct option is option d.

To know more about the principle of steering:

https://brainly.com/question/29458022

#SPJ6

Answer:

Does more sunlight make rose bushes grow taller?

Explanation:

When conducting a research, the researcher usually poses research questions in order to confirm or disprove the research hypothesis. A research question addresses the key issues and questions that the research project is intended to answer. Good research questions always aim at improving the body of knowledge on the selected topic of the research. Research questions must be narrowed down to specific details of the topic. They must also be testable, they must not be vague.

If I am studying the effect of sunlight on rose bushes, then the question, 'does more sunlight make rose bushes grow taller?' Is apt to the research because it can be tested by exposing various thorn bush plants to varying degrees of sunlight and recording my observation.

Answer:

If rose bushes receive more hours of sunlight each day, they will grow taller.

Explanation:

I just answered it on Apex, and they like to switch up how they word things sometimes.

Answer:

2.5 kg/m³

Explanation:

Absolute pressure = gauge pressure + atmospheric pressure

P = Pg + Pa

The gauge pressure caused by the weight of a fluid is called the static pressure.  It is equal to the density of the fluid × acceleration due to gravity × depth of the fluid,

Pg = ρgh

Therefore:

P = ρgh + Pa

300 Pa = ρ (10 m/s²) (8.00 m) + 100 Pa

ρ = 2.5 kg/m³

Answer:

A = [m/s]

B = [m/s²]

Explanation:

Assuming that V has SI units of m/s, then A and BT must also have units of m/s.

A = [m/s]

BT = [m/s]

Since T has SI units of s:

B [s] = [m/s]

B = [m/s²]