# Posts by Thien

Total # Posts: 7

**Math**

5/8 of the students in my class were boys. When 6 girls joined the class, the number of boys equaled the number of girls. How many students were in my class then?

**maths**

3/5 students are girls, so 2/5 students are boys. 200 = 2/5 boys therefore 1/5 = 100. Thus 3/5 girls = 300 Total: 500 students

**Chemistry**

Shouldn't it be +678 because the formula is E= deltaHf-(H sub + IE + HBE/2)- HEA?

**chemistry**

Why do you have to square Ag after you got the Molarity? -(0.00645)^2(0.0968)=4.03E-6

**Physics**

Nevermind Got it Block has two forces acting on it Horizontal force is the centripetal force acting towards center of circle Vertical force is M x G To get angle, its inverse Tan (MV^2/RMG)

**Physics**

A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 20.0 m/s, the block hangs vertically down. But when the van maintains this same speed around an unbanked curve (radius = 83.9 m), the block swings toward the outside of ...

**Chemistry**

density is mass/volume. Since they give you the mass of 55.81g already, you need to find the volume which is 24.7mL-17.6mL=7.10mL. 55.81g/7.10mL= 7.86 g/mL. mL=cm^3 so it becomes 7.86 g/cm3 or 7.86 gxcm^-3. The metal that matches this density is Iron.