Recent content by EricPowell

Homework Statement A car traveling at 88ft/s skids 176ft after its brakes are applied. The deceleration provided by the braking system is constant. What is its value? The Attempt at a Solution $$ v_0=88 \\ v_f=0 \\ d_0=0 \\ d_f=176 $$ $$ d(t)=\int88\,dt \\ d(t)=88t+c...

Just noticed that that question should say "Tim", not "Time". I should also note that my physics class is an introductory one. This question that I have posted was marked as "bonus" on the worksheet, so I would not be surprised if solving this question involves using something that we haven't...

Homework Statement Time tries to crush a 0.85kg basketball, but is only able to compress it by 1.5cm when a force of 50N in applied a) What is the spring constant of the ball? b) When he throws it against the floor, it is compressed by 3.4cm. How high will the ball bounce? Homework Equations...

NEVERMIND. I figured out my silly error. It's all good now. Can I delete this thread?

Okay I think I fixed all the formatting. Silly me.

I really messed up the formatting in that first post so it kind of looks like a mess. Until I figure that out, perhaps someone could point me in the right direction to solving the question?

Uhh I messed something up there with itex.

Homework Statement An open-topped cylinder is to have a volume of 250 cm3. The material for the bottom of the pot costs 4 cents per cm2, and the material for the side of the pot costs 2 cents per cm2. What dimensions will minimize the total cost of this pot? The Attempt at a Solution $$...

Homework Statement Find $$f'(-1)$$, given $$f(y) = h(g(y)), h(2) = 55, g(-1) = 2, h'(2) = -1$$, and $$g'(-1) = 7$$.Homework Equations Maybe the chain rule?The Attempt at a Solution I thought that I could create a function given that $$g(-1)=2$$, so I thought maybe the function could be...

Thank you so much for helping me Voko :)

##π∏## Just testing different pi symbols $$π∏$$

$$\frac {dA}{dr}=2πr$$ $$\frac {dr}{dt}=v$$ $$\frac {dA}{dt}=2πr×v$$ $$=2πvt×v$$ $$=2π \frac {5m}{s}×10s× \frac {5m}{s}$$ $$=2π×50m× \frac {5m}{s}$$ $$= \frac{1570.796m^2}{s}$$ Is this correct? Oh I messed something up there with my formatting. Ok fixed my formatting.

Why are my fractions so tiny?

Wait I think I get it. ##\frac {dr}{dt}= \frac {5m}{s}= \frac {r}{t}= \frac {vt}{t}= v##

I am so confused by all of this T_T Okay so...if I am understanding this right ##dr/dt## is the rate at which the radius changes with time. If the radius is changing at ##5m/s##, does that mean that ##dr/dt=r/t##?