Science & Mathematics - 21 October 2007

i need help. can anyone help me????

10. A 3.20 102 kg piano is being lifted at a steady speed from ground level straight up to an apartment 10.0 m above the ground. The crane that is doing the lifting produces a steady power of 4.00 102 W. How much time does it take to lift the piano?

12. A 50 g ball is thrown from a window with an initial velocity of 6.0 m/s at an angle of 30° above the horizontal.
(a) Using energy methods, determine the kinetic energy of the ball at the top of its flight.
(b) Determine its speed when it is 3.0 m below the window.

2007-10-21 14:52:44 · 1 answers · asked by flippin sweet 2 in Physics

be added to the 18 marbles already in the bag so that the probablity of randomly drawing a red marble is 3/5?

2007-10-21 14:47:46 · 2 answers · asked by dr.whooo 2 in Mathematics

Please explain how to solve this problem.

2007-10-21 14:44:19 · 9 answers · asked by Griselle A 1 in Mathematics

Given the situation in the figure below. The mass m1 is 0.64 kg and it is located at x1 = 30 cm. The pivot point is represented by the solid triangle located at x = 45 cm. The mass of the meter stick (mms = 0.40 kg) is located at its geometric center, xms = 50 cm. The mass m2 is 0.25 kg and it is located at x2 = 80 cm. Calculate the net torque (in N⋅m with the proper sign) due to these three weights. Use g = 9.8 m/s2.

There is a picture of a ruler with weights hanging at the locations listed above.

2007-10-21 14:44:11 · 1 answers · asked by Anonymous in Physics

Will a vector at 45 degrees to the horizontal be larger or smaller than its horizontal and vertical components ? By how much ? Explain why please !

2007-10-21 14:43:21 · 2 answers · asked by missybitsy 1 in Physics

I would like to know how to calculate thermocouple instead of using the table. Thanks.

2007-10-21 14:42:56 · 2 answers · asked by Craig L 1 in Engineering

A copper RTD is used. Its resistance at 32F is 100 ohms, and its temperature coefficient is 0.245 ohm/F. What is the ohms at 200F?

Please provide an equation instead of RTD table.

2007-10-21 14:42:00 · 1 answers · asked by Craig L 1 in Engineering

2007-10-21 14:41:58 · 10 answers · asked by Berry Nice 2 in Biology

solve intergral of ((3x)/(x2-6x+9))dx using partial fractions to determine the antiderivitive that passes through the point (4,0)

i'm stuck

2007-10-21 14:39:58 · 1 answers · asked by Rogi P 1 in Mathematics

2007-10-21 14:38:33 · 1 answers · asked by Anonymous in Mathematics

When you're looking at a plant under the microscope, how do you determine if the cells you're looking at are haploid or diploid?

2007-10-21 14:37:17 · 3 answers · asked by koreanboba 1 in Botany

2007-10-21 14:36:43 · 3 answers · asked by Anonymous in Earth Sciences & Geology

Steep lapse rates are often used to predict whether an innocent band of convective showers without any lightning could create enough static electricity to produce lightning and hence thunderstorms. During tornado season in the United States, you will often hear the term used a lot by meteorologists when severe convective weather is imminent.

2007-10-21 14:33:47 · 2 answers · asked by charlessmith702210@sbcglobal.net 6 in Weather

2007-10-21 14:33:25 · 4 answers · asked by questionareee 1 in Astronomy & Space

Please! I really need to know!!!

2007-10-21 14:33:19 · 15 answers · asked by Free S 1 in Geography

What would these two equations be when they are balanced:

H20 + SO2H2--->H2SO4

and

CaO2H2 + SO2--->CaSO4 + H2O

(the big numbers are supposed to be the little ones at the bottom of the letters...i just couldn't do it on the comp)

What type of chemical reaction are they synthesis, single replacement, double replacement, combustion, or decomposition?




Then:

Which reaction is endothermic or exothermic?

Enerygy + Reactant--->Product

Reactant--->Product + Energy

2007-10-21 14:31:34 · 2 answers · asked by Anonymous in Chemistry

A 3000 kg car is parked at the top of a 6.9 m long driveway that is sloped at 16 degrees with the horizontal. The parking brake fails. If an average friction force of 4100 N impedes the motion, find the speed of the car at the bottom of the driveway. The acceleration of gravity is 9.8 m/s^2. Answer in units of m/s.

2007-10-21 14:28:27 · 1 answers · asked by PhysicsDumbass 1 in Physics

2007-10-21 14:27:48 · 1 answers · asked by medsimas 2 in Physics

ughhh science hw :)

2007-10-21 14:26:52 · 7 answers · asked by freakychad 2 in Chemistry

whats the specific heat capacity of aluminium, iron, and copper
anf water too,,

2007-10-21 14:23:51 · 2 answers · asked by gunkedar 2 in Physics

How far out does space go? I can't imagine it coming to an end. However if it did come to an end, what is stopping you getting through it and what is behind that?

2007-10-21 14:23:17 · 8 answers · asked by Yogster 1 in Astronomy & Space

Is there a way to find the vertex of a circle? Like, say there is a circle and you need to find the diameter of it. You can only do that if you know where the vertex is so how do you do it?

2007-10-21 14:21:12 · 3 answers · asked by Josh 2 in Mathematics

A parachutist of mass 68.7 kg jumps out of an airplane at a height of 1080 m and lands on the ground with a speed of 5.9 m/s. The acceleration of gravity is 9.8 m/s^2. How much energy was lost to air friction during this jump? Answer in units of kJ.

Please show work/explanation of how you reached answer. Thank you.

2007-10-21 14:18:14 · 2 answers · asked by splashhhh 1 in Physics

The molar mass of a compound is measured to be 33.4, 35.2, 34.1 and 33.9 g/mol in four trials

a) what is the average molar mass of the compound

b) calculate the standard deviation for the determination of the molar mass


for A would I add the 4 number and divide by 4?

2007-10-21 14:17:54 · 1 answers · asked by bocabrunette714 1 in Chemistry

2007-10-21 14:15:16 · 6 answers · asked by jscreeker 1 in Astronomy & Space

f(x,y) = (e^ (-x^2-y^2) )(x^(2) +2y^(2));

D is the disk x^2 + y^2 < or equal 4.

2007-10-21 14:15:06 · 1 answers · asked by JOE 2 in Mathematics

An archer pulls her bow string back .324 m by exerting a force that increases uniformly from zero to 225 n. What is the equivalent spring constant of the bow? Answer in units of n/m.

b.) How much work is done in pulling the bow? Answer in units of J.

Please show work/explanation of how u arrived at your answer.

2007-10-21 14:14:22 · 1 answers · asked by splashhhh 1 in Physics

i'm making a math project and i have to work out the quadratic nth sequence and a friend told me that i also had to work out the general rule. but i tought the general rule and the quadratic nth sequence were the same thing ???

2007-10-21 14:11:49 · 1 answers · asked by Ruben N 3 in Mathematics

I realize that a double A has 1.5 Volts, but taking everything (including mAH of each) into consideration, I would like to know which would shine brightest and which would last longest.

2007-10-21 14:09:26 · 5 answers · asked by peachcobbler 3 in Physics

2007-10-21 14:09:04 · 9 answers · asked by Anonymous in Mathematics