# Posts by SARA

Total # Posts: 4,532

**physics**

A falling iPad takes 0.16 s to travel past a window 2.1 m tall. From what height above the top of the window did the mobile device fall?

**physics**

If a DeLorean rolls gently (vo = 0) off a vertical cliff, how long does it take it to reach a downward velocity of 78 km/h?

**physics**

A sophomore chemistry student holds a 500mL Erlenmeyer flask full of concentrated nitric acid high above his head at a height of 1.75 meters and declares, "I'm the King of Chemistry!" At that moment another student, startled by the sudden ignition of her Bunsen ...

**botany**

what is the difference between primary walls and secondary walls in plants. (specifically sclerencyma cells- which have secondary and parenchyma and collenchyma - which just have primary walls

**chem**

Draw the three distinct geometric isomers of 2,4-hexadiene. i can draw what it is giving. but i do not get what the geometric isomers are? if you drew it a different way wouldnt that change the name?

**Algebra..**

Help? If f = (1, 2), (2, 3), (3, 4), (4, 5), g = (1, -2), (3, -3), (5, -5), and h = (1, 0), (2, 1), (3, 2), 1. f+g 2. f-g 3. f*g

**Algebra..**

f(x)= x^2+3 ; g(x)=3x-1 Check These Please? 1.(fg)(-1) = 5 2. (f o g)(1) =10 How would you solve this? 1. (g o f)(x)

**physics**

A ping pong ball is rolling across a table at 2.1 cm/s. When the ball is 1.32 m away from the edge your little brother starts to blow on it. If the little doofus hopes to prevent the ball from falling off the edge, what minimum acceleration must be achieved?

**PHYSICS**

A Cessna 350 must reach a speed of 35 m/s for takeoff. If the plane accelerates at a steady 3.8 m/s2, how long must the runway be?

**PHYSICS**

When moving at highway speed, a Triumph America motorcycle is capable of accelerating at 2.1 m/s2. At this rate, how long does it take to accelerate from 103 km/h to 88 km/h?

**PHYSICS**

A ping pong ball is rolling across a table at 2.1 cm/s. When the ball is 1.32 m away from the edge your little brother starts to blow on it. If the little doofus hopes to prevent the ball from falling off the edge, what minimum acceleration must be achieved?

**chem**

Cobalt-60, which undergoes beta decay, has a half-life of 5.26 yr. (a) How many beta particles are emitted in 47.0 s by a 2.39-mg sample of 60Co? i got 2.44e19 but thast wrong

**physics**

When moving at highway speed, a Triumph America motorcycle is capable of accelerating at 2.1 m/s2. At this rate, how long does it take to accelerate from 103 km/h to 88 km/h?

**physics**

The minivan your mom lets you drive accelerates from 12 m/s to 24 m/s in 6.5 s. How far does it travel in this time? Assume constant acceleration.

**chem please help!**

The average energy released in the fission of a single uranium-235 nucleus is about 3. 10-11 J. If the conversion of this energy to electricity in a nuclear power plant is 45% efficient, what mass of uranium-235 undergoes fission in a year in a plant that produces 2000 megawatts

**Algebra..**

Help? If f = (1, 2), (2, 3), (3, 4), (4, 5), g = (1, -2), (3, -3), (5, -5), and h = (1, 0), (2, 1), (3, 2), Find and state the domain. 1. f+g 2. f-g 3.f*g

**pre algebra**

show the work for 136.8 divided by 3600

**Physics**

A baseball batter hits a long fly ball that rises to a height of 49 m. An outfielder on the opposing team can run at 7.7 m/s. What is the farthest the fielder can be from where the ball will land so that it is possible for him to catch the ball?

**chem**

A 73-kg person is accidentally exposed for 215 s to a 16-mCi source of beta radiation coming from a sample of 14C. What is the activity of the radiation source in disintegrations per second? In becquerels? i am not sure if there is an equation for this or wut??

**chem**

do you know how to do it using the numbers. I know for some problems uneeded information can be added but usually if its more than 2 peices then you use at least one of them

**chem**

it said that answers were wrong im pretty sure i have to use the 73 kg and 215 seconds.. or why would they put that in the question?

**chem**

I am not sure if there is an equation for this problem or wut?? A 73-kg person is accidentally exposed for 215 s to a 16-mCi source of beta radiation coming from a sample of 14C. What is the activity of the radiation source in disintegrations per second? In becquerels? (1 Ci...

**algebra**

art's age is two thirds cal's age, and bob is three years older than art. the sum of their three ages is 45. find the age of each one

**Physics**

A swimmer heads directly across a river, swimming at 1.10 m/s relative to the water. She arrives at a point 60.0 m downstream from the point directly across the river, 80.0 m wide. What is the speed of the river current? What is the swimmer's speed relative to the shore? ...

**math**

Two bulldozers clear homes from a 20-acre tract of land. One works twice as fast as the other. It takes them three days to clear the tract working together. How long would it take each of them alone? whats the equation?

**chemistry help!!**

I entered the asnwer I got and it is wrong.

**chemistry help!!**

thanks! so k=1.669e-11 so ln(65.3/45.9)=1.669e-11(t) so does t=2.112e10 years?

**chemistry help!!**

The half-life for the process 238U 206Pb is 4.5 109 yr. A mineral sample contains 45.9 mg of 238U and 16.8 mg of 206Pb. What is the age of the mineral? i used the equation: n(T)=n(O)/2^(t/halflife) and i got 6.53e9 but it is wrong. what am i doing wrong?

**math**

It just intersects at the point (0, -7), right?

**math**

So does this polynomial, when graphed, intersect the x-axis or it just comes close?

**math**

how many real roots does the polynomial 2x^5+8x-7 have

**statistics**

Thanks for the guidance. Does it make sense that I would get 1? 1. z = (x - μ) / σ z = (84-100)/8 z = -16/8 z = -2 and z = (116-100)/8 z = 16/8 z = 2 area = .0228+.9772 Area = 1

**statistics**

The mean of a normal probability distribution is 100 and the standard deviation is 8. About what percent of the observations lie between 84 and 116?

**Discrete Mathematics**

Mathematical sequences can be used to model real life applications. Suppose you want to construct a movie theater in your town. The number of seats in each row can be modeled by the formula C_n = 16 + 4n, when n refers to the nth row, and you need 50 rows of seats. (a) Write ...

**math**

for #1, where did you get the negative for - ( x+ 4 )

**math**

I tried solving these problems and get stuck . Can you please tell me what am I suppose to do next or did I do them all wrong 1. (x+5)^2 = (x+4)^2 √(x+5)^2 = √(x+4)^2 x+5 = x+4 ? 2. (4x+7)^2 = 144 √(4x+7)^2 = √144 4x+7 = 12 ? 3. (x-5)^2 = 30 √(x-5...

**Physics**

You drop a rock off a bridge. 4. (2 pts) How fast is it going after 2.0 s?

**chem**

i think it stands for alpha. so would i just do the U + alpha -> neutron +Pu?

**chem**

Write balanced equations for the following reactions. (Use the lowest possible coefficients. Omit states-of-matter in your answer. 238 U 92 (á, n) 241 Pu 94 sorry the formating is off

**math**

lithium citrate comes in 300 mg/5ml. the doctor calls and asks you to compound lithium citrate ''light'' (75mg/5ml). How would you dilute the citrate to proper dose?

**stumping question**

what is the difference between hydrofluoric acid and hydrogen fluoride. arnt they both HF?

**U.S. History**

I don't really understand the Spanish Colonial Empire during 33,000 b.c. to a.d. 1769 Who where involved? What was this? When did this take place? Where did this take place? Why is it so important?

**Reading**

May you please help me understand these questions? Thanks! 1. What does Spaz's story reveal about Spaz's origins? 2. With what is Spaz afflicted? In why way is it a blessing?

**Physics**

A helicopter is traveling with a velocity of 12 m/s directly upward. Directly below the helicopter is a very large and very soft pillow. As it turns out, this is a good thing, because the helicopter is lifting a large man. When the man is 20 m above the pillow, he lets go of ...

**Physics**

You are standing at the foot of the Bank of America building in San Francisco, which is 52 floors (237 m) high. You launch a ball straight up in the air from the edge of the foot of the building. The initial vertical speed is 70 m/s. a. How high up does the ball go? b. How ...

**Reading**

In this book I'm reading one of the questions ask: What is the significance of Bean finding the color blue? What does the question mean?

**chem**

what is the symbol for the element that has 78 protons 76 electrons 117 neutrons and a +2 net charge? i thought it was ^195Os^+2 but that is wrong. Thanks for the help!

**Physic**

If a clock in an airplane is found to slow down by 5 parts in 1013, (i.e., ∆t/∆to = 1.0 + 5.0 × 10. −13), at what speed is the airplane traveling? (Hint: You might need to use an expansion for y) I am not sure which equation to use can someone please ...

**Physic**

A sodium-vapour lamp illuminates, with monochromatic yellow light, two narrow slits that are 1.00 mm apart. if the viewing screen is 1.00m from the slits and the distance from the central bright line to the next bright line is 0.589 mm, what is the wavelength of the light? can...

**Physics**

On your wedding day your lover gives you a gold ring of mass 3.78 g. 50 years later its mass is 3.16 g. On the average how many atoms were abrated from the ring during each second of your marriage? The atomic mass of gold is 197 u

**Social Studies**

sorry. c?

**Social Studies**

is it d then?

**Social Studies**

Following on the successful activism of Cesar Chavez, Mexican American youths began to refer to themselves as A. Mexicans. B. Los Barrios. C. Chicanos. D. Los Hombres. is it a?

**Social Studies**

The 1978 Supreme Court decision in Bakke v. Regents of the University of California A. ruled in favor of affirmative action within specified limits. B. established the "red state-blue state" divide. C. established the rights of students to appeal college admissions ...

**Social Studies**

THE FIRST ONE IS WRONG

**Social Studies**

Which of the following statements about Truman's Fair Deal is true? A. It was reluctantly passed by Congress. B. It repealed the New Deal. C. It was Truman's response to the Soviet's Sputnik. D. It called for national medical insurance. is it d?

**Social Studies**

The majority of states that did not ratify the Equal Rights Amendment were located in the A. Midwest. B. Southeast. C. West. D. Northeast. is it B?

**Social Studies**

During World War II, the tide turned in favor of the United States at the Battle of A. Leyte Gulf. B. Okinawa. C. Midway. D. the Coral Sea. is it C??

**Home economics**

I need help on a hw question. Can a company bill you if you just give them your billing address or do they need a credit card number(or some type of payment)

**Science**

#9 is d?

**Science**

#3 is D?

**Science**

Okay. Is #1 B? Because it does support life. I know that. Coal isn't manufactured, & isn't in a liquid form, and it is organic. Is #9 b, as well?

**Science**

9. Which one of the following statements is characteristic of liquid water? A. It has a definite shape but not a definite volume. B. It has neither a definite shape nor a definite volume. C. It has a definite volume and a definite shape. D. It has a definite volume but not a ...

**Physics**

what is 5.76??

**Physics**

3 charges sit on vertical equilateral triangle the side of each is 30.0 cm. if the triangle are A= +4.0 uC B=+5.0 uC and C=+6.0 uC (clockwise from top) what is the force on each charge? Can someone please explain me in detail i am really confuse :(((

**math**

Sorry, I meant A.

**math**

The quotient of 5/31 divided by 15/23, reduced to the lowest fraction, is A. 23/93. B. 93/23 or 4 1/23. C. 75/373. D. 115/465. Is it b?

**Math**

D?

**Math**

The amount $180.00 is what percent greater than $135.00? A. 35% B. 75% C. 133.33% D. 33.33% Is it b?

**MATH**

You wish to mentally estimate the total cost of items that have the following prices: $1.85, $.98, $3.49, $9.78, and $6.18. Rounding off the items to the nearest half-dollar, your estimate of the total cost of these items is A. $22.50. B. $22.30. C. $22.59. D. $23.00. Is it A??

**Physic**

The field of an unknown charges is first mapped with a 1.0 X 10^-8 C test charges, then repeated with 2.0 X 10^-8 C test charge. a) would the same forces be measured with the two test charges (Explain)? b) would the same fields be determine using the two test charges (Explain)?

**physical**

But if i do this for force of friction, the result of frictional force is going to be negative. :(

**physical**

A 0.8 kg block of wood has an initial velocity of 0.25 m/s as it begins to slide across a table. The block comes to rest over a distance of 0.72m. a) what is the average frictional force on the block? b)How much work is done on the block by friction? c)How much work is done on...

**physic**

3 charges sit on vertical equilateral triangle the side of each is 30.0 cm. if the triangle are A= +4.0 uC B=+5.0 uC and C=+6.0 uC (clockwise from top) what is the force on each charge?

**English**

What is a cliche and what is a sentence that's an example?

**English**

Identify the sentence that contains a noun clause in italics. A. What Betty wants is to harvest the corn. B. When should Betty harvest the corn? C. Betty wants to harvest the corn. D. Betty would like to harvest the corn. Is it D?

**English**

Which one of the following is a correct example of the plural possessive case? A. woman's plans B. it's place C. men's plans D. stone's throw is it a?

**English**

is it C?

**English**

Choose the sentence that has a compound predicate. A. Sandy washed and ironed her clothes. B. Sue and I will listen. C. We went home to eat and to study. D. Swimming and golfing are Jim's favorite sports. Is it D?

**english**

So it's A?

**english**

Choose the correct singular, third person, conjugation of the verb to be in the future perfect tense. A. You have been B. I will be C. She will have been D. They will have been is it D?

**English**

In the following sentence, what is the subject complement? My neighbor is a newspaper reporter. A. Reporter B. My C. Neighbor D. Newspaper Is it A?

**English**

Which kind of adjective is used most frequently in ordinary speech or writing? A. Proper B. Common C. Article D. Demonstrative Is it B?

**English**

in*

**English**

In the following sentence, identify the part of speech of the italicized word. Thousands of years ago, fish were caught in nets and traps. A. Verb B. Preposition C. Pronoun D. Conjunction Is it B?

**Algebra2**

Sorry "being" shouldn't have been there. Another mistake!

**Algebra2**

Lol:D You were being speeding threw the problems just like me! i did that in problem 4! I got the right answer now! Thank you!

**Algebra2**

I think i know what i did wrong in problem 4! My multiplication is wrong!

**Algebra2**

I went back and I corrected problem 2 and 3. In problem 2 I found my mistake, But in problems 1 and 4 I'm stuck and can't figure out how you got those answers. I did the problems at least 4 times already and I keep getting the same answers:/

**Algebra2**

I Made a Mistake Problem #4 Answer Is 21-20i

**Algebra2**

Check Answers Please? 1. 5+(2+3i) + (-3-7i) = 4 + -4i 2. (5-10i) - (2+i) = 7 - 9i 3. -5i(2-3i) = -10i - 15 4. (2+3i)(-3-7i) = (1)(4i)

**Algebra2**

Thanks! I Seen My Mistakes and Fix Them. Thank You .

**Algebra2**

Can Someone Check My Anwsers? 1. -17=10x+3 = x=2 2.9x+5=7x+3x-2 = x= 7/1= 7 #I Do Have My Work Shown, On a Separate Sheet Of Paper . But I Want to Know If I Got My Answers Right.

**Algebra2**

Oh Okay . I Tried The Other Two Problems. For #1 I Got 120 As My Answer. For #2 I Got 37 As My Answer.

**Social Studies**

I have. Is it A?

**Social Studies**

When postwar expansion slowed in the 1950s, an economic stimulus was provided by A. increased consumer goods manufacturing. B. the baby boom. C. Cold War spending. D. the construction of Levitt Towns. Is it B?

**Social Studies**

So, it's A?

**Social Studies**

At the beginning of World War II, Roosevelt dealt with France A. by supporting the Free French under Charles de Gaulle. B. by seeking an alliance with French Algeria. C. by joining with the British in an assault on North Africa. D. through negotiations with the Vichy ...

**Social Studies**

During the election of 1936, declaring their party a "millionaire's union," Franklin Roosevelt focused mainly on defeating the A. Union Party running William Lemke. B. Liberty League running Alfred M. Landon. C. Liberty League running Father Coughlin. D. Union ...

**Social Studies**

B. Band Concerts?