Posts by Mable

Total # Posts: 41

physics
You're driving on the freeway going 90km per hour and it starts to rain. The raindrops make an angle of 40 degrees with the vertical when viewed through the driver's side window. What is the speed of the raindrops measured by someone at rest relative to the freeway? ...

biology
Are the DNA template strand and the mRNA sequences similar, or complementary? Are the DNA coding strand and the mRNA sequences similar, or complementary? Are the DNA template and the DNA coding strand sequences similar, or complementary?

physics
A person is running from a cliff into a pond. The cliff has a height of 10.0m above the water but it is not strictly vertical, it slopes down to the pond at an angle of 40 degrees with respect to the vertical. What is the minimum speed the person needs to jump from the cliff ...

calculus
It is a dark clear night. The air temperature is 15? C. A body is discovered at midnight. Its temperature is 23? C. One hour later, the body has cooled to 20? C. Use Newton’s law of cooling to determine the time of death.

calculus
find dt/dx t=((a^2+x^2)^1/2)/v1 + ((d^2+b^2)^1/2)/v2

calculus-snell's law
Suppose A light ray starts at the point A = (0,a) in an uniform medium 1 where the speed of light is c1 and then passes through an uniform medium 2 where the speed of light is c2 reaching point B = (d, ?b). The line separating the two media is the x-axis; HINTS ONLY 1) what is...

Algebra
collect like terms and simplify 4x^2-5x^2=-x^2 -3x=8x-11x 8=6+2 final answer : -x^2-3x +8

Algebra
collect like terms -- remember that double negatives makes a positive

calculus- optimization
A rectangle is inscribed into a semi circle at radius 2. What is the largest area it can have and what are the dimensions Answers Area= 4 max base =2sqrt2 height = sqrt2 Help is always appreciated :)

calculus
it is assumed that f is differentiable and that w has an absolute maximum at t0 w(t)= f(t)/(c+t) derivative is f'(t)(c+t)-f(t)/(c+t)^2 Show that f(t0) = f?(t0)(C + t0). I'm having a bit of trouble in the above question. I keep getting f(t0)= (c+t0)-f'(t0) instead ...

calculus
it is assumed that f is differentiable and that w has an absolute maximum at t0 Show that f(t0) = f?(t0)(C + t0).

calculus
w(t)= f(t)/(c+t) w'(t)=? I got f'(t)(c+t)-f(t)/(c+t)^2 as the derivative and I'm having a hard time trying to prove that f(t_0) = f'(t_0) (C+t_0) Help is always appreciated :)

calculus
One litre of water at 0 degrees Celsius will have a different volume at higher temperatures. For a temperature 0 ? T ? 30 (in Celsius) this volume (in litres) is well approximated by the function V = ?aT 3 + bT 2 ? cT + 1 using the coefficients a = 9.8 × 10?8, b = 3.5 &...

math plzzz help quick
(1) x-y=-11 (2) y+7=-2x rearrange the equation 1 to get y by itself -> x=-11+y substitute that in equation 2 y+7=-2(-11+y) and solve for y

physics
A positive charge with Q1= +2?10-6 C and a negative charge Q2 = -1×10-6 C are located at an equal distance 0.1m from the origin (see below). A third charge Q3=+1?10-6C is located at the origin. Calculate the magnitude of the net force exerted on charge Q3 Calculate the ...

physics
A 2 kg block with initial velocity +2m/s collides with a stationary 6 kg block with initial velocity 0m/s on a frictionless surface. After the collision, the 2 kg block is moving at –1 m/s and the 6kg block is moving to the right at +1 m/s. Show that the total momentum is...

physics
A 100 kg car is traveling at 20m/s over the top of a circular hill as shown below. The radius of the circle is 200 m. What force does the ground exert on the car at the top of the hill? After reaching the top of the hill, the car descends a vertical distance of 20 m. What is ...

physics
A 2 kg block is being pulled by a rope with a tension of 3N at an angle of 45° as shown. The coefficients of friction are μk=0.4 and μs=0.5. Does the block slide or not?

physics
A 0.035 kg spherical oil droplet has charge of +1×10-7C. A uniform electric field is acting upwards as shown below. What strength of electric field is required to make the sphere float in the air without moving?

physics
A 1000 kg car is initially at rest. If the motor does 10,000J of work on the car, what is the car’s final speed? (Neglect friction, and assume that the car is on level ground.)

physics
A 5kg block has an initial velocity of 15 m/s and is sliding along a surface with friction. Eventually the block comes to rest. what is the change in thermal energy of the block and the surface ?

physics
a stone that is thrown near the surface of the earth. There is no air resistance. Position increases in the up direction. The initial velocity is 30 m/s at 30 degrees above the horizontal. what is the velocity when the stone reaches its maximum height ? what is the ...

physics
Car A with a mass of 1000kg is travelling east at 25m/s when it collides with car B, 2000kg, travelling north at 15m/s. After the collision, the two cars stick together and have the same velocity. Assume that they slide without friction after collision. (a) What is the final ...

geometry
A drug company is testing new toothpaste in 2 flavors, regular and cinnamon. In a sample of 193 people, 121 liked regular, 112 people liked cinnamon, and 46 liked both.

science
how many atoms of magnesium are in the magnesium molecule?

hhs 265 accounting
calculating the current ratio of the XYZ nonprofit corporation balance sheet using appendix b.

chemistry
How many grams of copper is deposited from an aqueous solution of copper sulfate, (CuSO4(aq)), by passing one mole of electrons into a copper plating cell? A. 254g B. 127g D. 42.3g E. 31.8g

chemistry
The compound with the highest boiling point will be which of the following? A.CH3Cl B.CH3Br C.CH4 D.CH3F

chemistry
Carbon is able to form large numbers of organic compounds because carbon can A.form 4 bonds B.form single, double and triple bonds C.form chains, rings, spheres and sheets D.the carbon-carbon bond is very stable E.all answers are correct

chemistry
The melting point of a compound is not influenced by which of the following? A. polarity B. electronegativity of its atoms C. Van der Waals forces D. hydrogen bonds E. isotope of carbon

chemistry
An amine is characterized by what functional group? A.-CO2CH3 B.-NH2 C.-CO2H D.-CHO E.-OH

chemistry
Esters are A.found in some medicines B.often fragrant C.essential oils in fruits and flower D.found in some types of flavorings E.all answers are correct

chemistry
Suggest a type of reaction and the conditions required to breakdown polyamides into their monomers.

chemistry
Draw three repeating units of the condensation polymer made from ethanedioic acid and ethanediol. if anyone has a weblink that illustrates this may you please send it?

chemistry
Suggest a type of reaction and the conditions required to breakdown polyamides into their monomers.

chemistry
Construct the following using molecules of your choice: a) a polyester and b) a polyamide. Each drawing should have four monomers and should be original in its structure. Your polymers can not be biochemical (carbohydrate, lipid, protein, etc.). Identify the reactions as ...

chemistry
What types of linkage joins the nucleotides a) within a single DNA strand and b) between two single DNA strands?

chemistry
Explain in terms of molecular structure why sugars have a relatively high melting point compared to hydrocarbons of a similar size.

chemistry
Explain in terms of molecular structure why sugars have a relatively high melting point compared to hydrocarbons of a similar size.

algebra
Quartics using P(X) = af(b(x-c)+d Recall Q(X) = (x-2)(x-1)(x+1)(x+2) a)Choosing a (i) Rewrite Q(x) for a. Let b = 1, c = 0 and d = 0 (ii) Make 3 copies of the same function on your calculator Let a= -1, 1 and 2 Your equations are Y1= __________(a=-1) Y2= __________(a=1) Y3= ...

chemistry
What functional group(s) must be present in a monomer of a condensation reaction?