Recent content by LoveandHate

Homework Statement I have to prove that 3A=(cos(2A)-cos(4A))/(sin(4A)-sin(2A)) Homework Equations All of the trig identites. The Attempt at a Solution Well, I know I can expand tan(3A) to sin(3A)/cos(3A). After this, I have no idea what to do. I do not know any way to simplify or...

yeahh. i completely understand what you did. i did that too, but i don't want to assume that (1, -2) is the vertex if they don't tell me. the question says: "Determine the equation of a quadratic function that satisfies each set of conditions. b) x-intercept 3, and passing through the point (1...

well i assumed, because they only gave me one zero, that that was the vertex of the the parabola. but the discriminant is larger than zero, so it has two. i was going to use the vertex form of the equartion, but that obviously won't work now. the answer in my book is y=-2x^2-3x+3. this equation...

thanks, but what point do i use?

stupid question, but if i know a zero of a parabola and a point it goes through, how do i find it's equation?

i have to do it the kinematics way.. don't confuse me with the energy just yet! haha.

Homework Statement A marble rolls off a table with a velocity of 1.93 m/s [horiz]. The tabletop is 76.5 cm above the floor. If air resistance is negligible, determine the velocity at impact. -\Deltat has been found in a previous question; =0.395 s -I know the answer is 4.33 m/s [63.5 degrees...

Homework Statement So, I have a 5.0 kg rat that goes down a ski slope, slides along a rough patch, and then smashes into a vertical board with a spring attached. I need to find out the efficiency of the spring with this information: m=5.0 kg v (after sliding across rough patch)=108 m/s ; it...

I know, and I'm sorry I'm being confusing. I'm just confused with the whole concept, but I think I may understand, if not fully, than a lot better than before.

I understand all of this, but why was I told to use Earth's radius as distance?

we haven't learned that yet! and I'm confused by what you said.

Homework Statement A 2.5 kg cat is fired horizontally out of a cannon across a frozen lake. It is wearing steel tap shoes. The kinetic coefficient of friction is 0.010. If the cat's initial speed was 200 km/h, then: a) does the cat make it all the way across the 1.0 km wide lake? b) if so...

So, because of the shape of the Earth, the gravitational force is stronger at the poles than at the equator. And can you explain the part about density? How does this effect the formula?

The force of gravity on Earth attracts things to the centre of the Earth, no? I understand why the gravitational force is less on mountains, as one is farther away from the centre of the Earth, so when using Fg=GMm/d2, then distance is larger, therefore the squared number would be larger than at...