How long does it take a car to cross a 20m bridge if it starts from rest and accelerates at 5 m/s^2?
2s
1.89s
1.41s
1.41 m
2.8s

Answer:

C

Explanation:

Answer:

Centripetal force is the force that is necessary to keep an object moving in a curved path and that is directed inward toward the center of rotation, while centrifugal force is the apparent force that is felt by an object moving in a curved path that acts outwardly away from the center of rotation

Explanation:

Hope this helps!

Brainliest if correct pls

Answer:

It depends on how much you stress I recommend starting calm!

Explanation:

Answer:

I'm a senior right now, but I think the subjects gradually get more difficult, it's not all too difficult though, it's just stressful because the amount of work your expected to finish.

Explanation:

Answer:

Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.

Explanation:

:)

Answer: The complete length of the path between any two points is called distance. Displacement is the direct length between any two points when measured along the minimum path between them.

Explanation: It's what's!!

Answer:

disassemble, break apart,divide, separate

Explanation:

just know and have learned it....

Answer:

[tex] \boxed{\sf Potential \ energy \ (PE) = 7.35 \ kJ} [/tex]

Given:

Mass (m) = 75 kg

Height (h) = 10 m

Acceleration due to gravity (g) = 9.8 m/s²

To Find:

Potential Energy (PE)

Explanation:

The formula for potential energy due to gravity:

[tex] \boxed{ \bold{PE = mgh}}[/tex]

Substituting value of m, g & h in the formula:

[tex] \sf \implies PE = 75 \times 10 \times 9.8 \\ \\ \sf \implies PE = 7350 \: J \\ \\ \sf \implies PE = 7.35 \: kJ[/tex]

Answer:

Third charge should be placed at a distance d/3

Sign is negative

Magnitude is |q| = 4Q/3

Explanation:

To find a place where a third charge, q, is placed so that all three charges will be in equilibrium would be at;

E1 = E2

Now, let the distance between the charges +Q and +4Q be d. Also, let the distance from charge +Q to the third charge q be x.

Thus;

E1 = kQ/x²

E2 = k(4Q)/(d - x)²

Since equilibrium, then;

E1 = E2 gives;

kQ/x² = k(4Q)/(d - x)²

k and Q will cancel out to give;

1/x² = 4/(d - x)²

Cross multiply to get;

(d - x)² = 4x²

Taking square root of both sides gives;

√(d - x)² = √4x²

Gives;

d - x = 2x

d = x + 2x

d = 3x

x = d/3

This is the point at which E1 = E2.

Since at equilibrium, it means that Fq + F2 = 0

Now, electric force formula is;

F = kq1*q2/r²

So; Fq = kqQ/x²

F2 = kQ(4Q)/d²

Equating Fq + F2 = 0 gives;

kqQ/x² + kQ(4Q)/d² = 0

kqQ/x² = -kQ(4Q)/d²

Like terms cancel out to get;

q/x² = -4Q/d²

q = - 4Qx²/d²

earlier we saw that x = d/3.

So, q = -4Q × (d/3)²/d²

q = -4Q × ⅓

q = - 4Q/3

Thus,it's sign is negative.

It's magnitude will be the positive value.

Thus, magnitude is;

|q| = 4Q/3

1). The sign that will be of all the given three charges being in equilibrium would be:

A). Negative

2). The magnitude to allow all the given three charges to remain in equilibrium would be:

- Magnitude [tex]|q| = 4Q/3[/tex]

Given that,

First Charge [tex]= +Q[/tex]

Second Charge[tex]= +4Q[/tex]

Third Charge [tex]= q[/tex]

The location where they will be in equilibrium would be:

[tex]E1 = E2[/tex]

So,

We will assume the distance between the first two charges i.e. +Q and +4Q as d and assume the distance from charge +Q to the third charge q as x.

Now,

[tex]E1 = kQ/x^2[/tex]

[tex]E2 = k(4Q)/(d - x)^2[/tex]

Therefore,

The equilibrium will be at:

[tex]kQ/x^2 = k(4Q)/(d - x)^2[/tex]

by solving we get,

[tex]x = d/3[/tex]

Because at equilibrium [tex]Fq + F2 = 0[/tex],

So,

F [tex]= kq1*q2/r^2[/tex]

and [tex]Fq = kqQ/x^2[/tex]

[tex]F2 = kQ(4Q)/d^2[/tex]

by resolving the equation, we get;

[tex]Fq + F2 = 0[/tex]

[tex]kqQ/x^2 + kQ(4Q)/d^2 = 0[/tex]

By solving it, we get

[tex]Magnitude(q) = - 4Q/3[/tex]

Thus, the sign is negative.  

and Magnitude |q| = 4Q/3

Thus, options A and [tex]|q| = 4Q/3[/tex] would be the correct answer.

Learn more about "Charge" here:

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Answer:

[tex] \boxed{ \bold{ \huge{ \boxed {\sf{8.33 \: m \:/s \: }}}}} [/tex]

Explanation:

Distance travelled = 200 metre

Time taken = 24 second

Velocity = ?

Finding the velocity

[tex] \boxed{ \sf{velocity = \frac{distance \: travelled \: }{time \: taken}}} [/tex]

[tex] \dashrightarrow{ \sf{velocity = \frac{200 \: m}{24 \: s} }}[/tex]

[tex] \dashrightarrow{ \sf{velocity = 8.33 \: m/s}}[/tex]

Hope I helped!

Best regards!

Answer:Three elements make up over 99.9 percent of the composition of dry air: these are nitrogen, oxygen, and argon.

Explanation:

Answer: Air is an gaseous substance

Explanation:

Air is a homogeneous mixture of the gaseous substances nitrogen, oxygen, and smaller amounts of other substances. Salt, sugar, and many other substances dissolve in water to form homogeneous mixtures.

Answer:

distance=speed×time.

45×20=900m.

Answer:

a

Explanation:

Answer:

Fossil Fuels are natural fuels like coal or gas that were formed millions of years ago and take millions of years to form. They are formed from the remains of past living organisms.

Explanation:

Well you do no really need an explanation for this one...

Answer:

7.43 m/s

Explanation:

Time taken for car to stop = 7.0 s

distance traveled before coming to rest = 26 m

Final speed of the car = 0 m/s (since it stops)

initial speed of the car = ?

To get the final speed, we use the equation

s = [tex]\frac{1}{2}t(u + v)[/tex]

where

s is the distance traveled before stopping

u is the initial speed = ?

v is the final speed = 0 m/s

t is the time = 7 s

substituting values, we have

26 = [tex]\frac{1}{2}*7*(u + 0)[/tex]

26 = 3.5u

u = 26/3.5 = 7.43 m/s

Answer:

answer is 0m/ sec

please follow me.

Answer:

0.543 kilogram

Explanation:

thats the answer

Answer:

Hey there!

Flammability is a chemical property. It doesn't change based on what state of matter the object is in.

Let me know if this helps :)

Answer:Flamibilliety

Explanation:

Answer:

different temperatures

Explanation:

The independent variable would be different temperatures.

The independent variable is the variable that is manipulated or varied in an experiment in order to see the effects it will produce on another variable - the dependent variable. The values of the independent variable are directly inputted by the researcher and are not changed by any other variable throughout the experiment.

In the illustration, the effect of a variation in temperature is determined by counting the number of yeast cells. This showed that the manipulated variable is the temperature and hence, the independent variable.

Answer:

[tex] \boxed{\sf Heat \ produced \ (H) = 5 \ kWh} [/tex]

Given:

Resistance (R) = 100 Ω

Current (I) = 5 A

Time (t) = 2 hours

To Find:

Heat developed (H) in the electric iron

Explanation:

Formula:

[tex] \boxed{ \bold{ \sf H = I^2Rt}}[/tex]

Substituting values of I, R & t in the equation:

[tex] \sf \implies H = {5}^{2} \times 100 \times 2 \\ \\ \sf \implies H = 25 \times 100 \times 2 \\ \\ \sf \implies H = 5000 \\ \\ \sf \implies H = 5 \: kWh [/tex]

[tex] \therefore[/tex]

Heat developed (H) in the electric iron = 15 kWh

Answer:

The roadrunner will take approximately 5.285 seconds to catch up to the rattlesnake.

Explanation:

From the statement we notice that:

1) Rattlesnake moves a constant speed ([tex]v_{S} = 0.75\,\frac{m}{s}[/tex]), whereas the roadrunner accelerates uniformly from rest. ([tex]v_{o, R} = 0\,\frac{m}{s}[/tex], [tex]a = 1\,\frac{m}{s^{2}}[/tex])

2) Initial distance between the roadrunner and rattlesnake is 10 meters. ([tex]x_{o, R} = 0\,m[/tex], [tex]x_{o,S} = 10\,m[/tex])

3) The roadrunner catches up to the snake at the end. ([tex]x_{S} = x_{R}[/tex])

Now we construct kinematic expression for each animal:

Rattlesnake

[tex]x_{S} = x_{o,S}+v_{S}\cdot t[/tex]

Where:

[tex]x_{o, S}[/tex] - Initial position of the rattlesnake, measured in meters.

[tex]x_{S}[/tex] - Final position of the rattlesnake, measured in meters.

[tex]v_{S}[/tex] - Speed of the rattlesnake, measured in meters per second.

[tex]t[/tex] - Time, measured in seconds.

Roadrunner

[tex]x_{R} = x_{o,R} +v_{o,R}\cdot t +\frac{1}{2}\cdot a\cdot t^{2}[/tex]

Where:

[tex]x_{o, R}[/tex] - Initial position of the roadrunner, measured in meters.

[tex]x_{R}[/tex] - Final position of the roadrunner, measured in meters.

[tex]v_{o,R}[/tex] - Initial speed of the roadrunner, measured in meters per second.

[tex]a[/tex] - Acceleration of the roadrunner, measured in meters per square second.

[tex]t[/tex] - Time, measured in seconds.

By eliminating the final positions of both creatures, we get the resulting quadratic function:

[tex]x_{o,S}+v_{S}\cdot t = x_{o,R}+v_{o,R}\cdot t +\frac{1}{2}\cdot a \cdot t^{2}[/tex]

[tex]\frac{1}{2}\cdot a \cdot t^{2} + (v_{o,R}-v_{S})\cdot t + (x_{o,R}-x_{o,S}) = 0[/tex]

If we know that [tex]a = 1\,\frac{m}{s^{2}}[/tex], [tex]v_{o, R} = 0\,\frac{m}{s}[/tex], [tex]v_{S} = 0.75\,\frac{m}{s}[/tex], [tex]x_{o, R} = 0\,m[/tex] and [tex]x_{o,S} = 10\,m[/tex], the resulting expression is:

[tex]0.5\cdot t^{2}-0.75\cdot t -10=0[/tex]

We can find its root via Quadratic Formula:

[tex]t_{1,2} = \frac{-(-0.75)\pm \sqrt{(-0.75)^{2}-4\cdot (0.5)\cdot (-10)}}{2\cdot (0.5)}[/tex]

[tex]t_{1,2} = \frac{3}{4}\pm \frac{\sqrt{329}}{4}[/tex]

Roots are [tex]t_{1} \approx 5.285\,s[/tex] and [tex]t_{2}\approx -3.785\,s[/tex], respectively. Both are valid mathematically, but only the first one is valid physically. Hence, the roadrunner will take approximately 5.285 seconds to catch up to the rattlesnake.

Answer:C.

Explanation:

The rate of change in velocity; speeding up, slowing down, or changing direction

Given :

Mass of block , M = 20 kg .

Force applied , F = 80 N .

Acceleration of block , [tex]a=2.5\ m/s^2[/tex] .

To Find :

The coefficient is Kinetic force friction between the block and the table .

Solution :

We know , Force equation on block is given by :

[tex]F_{net }=F-\mu_k mg \\\\ma = F-\mu_k mg \\\\20\times 2.5 = 80 -\mu_k \times 20 \times 10\\\\\mu_k\times 200=30\\\\\mu_k=\dfrac{30}{200}\\\\\ mu_k=0.15[/tex]

Therefore , coefficient is Kinetic force friction between the block and the table is 0.15 .

Hence , this is the required solution .

Answer:

Models are useful for developing scientific methods.

Explanation:

Which statement describes an advantage of models? And Developing is an advantage of a model.

Developing scientific methods.

"The scientific method is a process for experimentation that is used to explore observations and answer questions."

The scientific method has five basic steps, plus one feedback step:

Know more about models here

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Answer:

Power is a measure of the amount of work that can be done in a given amount of time. So, the formula is the energy or work divided by time:

P = W ÷ T, where p is power , w is work and t is time.

Answer:

____________

in real world conditions?

it seems the most plausible.

Answer (B)

Cars are tested on closed tracks and race tracks so rule out A, D. Tha leaves us with B, C. C is kind of a real-world situation so the answer is most likely, B.