# Hao

Most popular questions and responses by Hao
1. ## I NEED HELP PLEASE

A trough is 8 meters long, 3 meters wide, and 5 meters deep. The vertical cross-section of the trough parallel to an end is shaped like an isoceles triangle (with height 5 meters, and base, on top, of length 3 meters). The trough is full of water (density

2. ## Math

A trough is 8 meters long, 3 meters wide, and 5 meters deep. The vertical cross-section of the trough parallel to an end is shaped like an isoceles triangle (with height 5 meters, and base, on top, of length 3 meters). The trough is full of water (density

3. ## chemistry

In hydrated copper sulfate, the chemical formula is CuSO4.5H2O, while that of hydrated cobalt(II) chloride is CoCl2.6H2O. I want to ask how to determine the number of moles of water is needed to hydrate any salt. Is there a pattern or formula?

4. ## Thermodynamics

A 10m height cylinder with cross sectional area of 0.1 m2 has a massless piston at the bottom as shown in Figure Q2. Water is at the top of the piston with air at 20oC over it. Under the piston there is air at 300K. The volume of the air is 0.3m3. Heat is

5. ## Physics

If the work required to stretch a spring 4 feet beyond its natural length is 17 foot-pounds, how much work is needed to stretch it 14 inches beyond its natural length? Your answer must include the correct units. (You may enter lbf or lb*ft for ft-lb.)

6. ## Chemistry

Is boron trichloride a Giant covalent or Simple molecular substance?

7. ## Thermodynamics

A 10m height cylinder with cross sectional area of 0.1 m2 has a massless piston at the bottom as shown in Figure Q2. Water is at the top of the piston with air at 20oC over it. Under the piston there is air at 300K. The volume of the air is 0.3m3. Heat is

8. ## math

It is known that the number of people who enter a bank during a time interval of t minutes is a Poisson random variable with the parameter t. The bank opens at 8am and you arrive at the bank at uniformly random time between 8am and 9am. Let X be the

9. ## Chemistry

Which of the following is not suitable for testing the presence of an acid? A) adding aqueous potassium carbonate. B) adding aqueous potassium hydroxide. C) adding Universal Indicator. D) adding zinc powder. Personally, I feel that all of them are

10. ## science

To have a high work effiency of concrete batching plant,we need to know the maintance of it to extend its useful life.We have study this for a long time and it includes two aspects. One is lubricating the shaft of concrete batching plant when it works

11. ## Math

Water is flowing into a trough at a rate of 100 cubic centimeters per second. The trough has a length of 3 meters and cross sections in the form of a trapezoid, whose height is 50 cm, whose lower base is 25 cm and whose upper base is 1 meter. At what rate

12. ## maths

what is 454456x45647+344554564-44453287= with out using a Calculator

13. ## maths

what is 453776578665432 x 3467+3244325-34677797= [with out using a Calculator.

14. ## math

what is 1255 to the nearest 3000

15. ## chemistry

What is formed when zinc carbonate reacts with concentrated hydrochloric acid?

16. ## chemistry

How to perform an experiment to distinguish between zinc(II) hydroxide and magnesium hydroxide?