Recent content by Dyna

Efficiency = useful output / input x 100% .8 = 2.0 x 10 ^12 J / input x 100% no i have no idea what I am doing XD help?

So..the house needs 2.0 x 10^9 kJ... so thats...( 2 x 10^12 x .8) = e/ m what would E be here - 5.5 x 10 ^7 ?

1. Methane has a heat of combustion of 5.5 x 10^7 J/kJ. a)How much gas is required to heat a house that requires 2.0 x10^9 kJ for the whoel winter? Assume that the furnace is 80% efficient 3. So i tried dividing using Q=mL but i don't seem to be getting the right answer (4.5 x 10^5) I also...

1. Calculate the gravitational field constants for the following: Mars (r=3.43 x 10^6m , m= 6.37 x 10^23 kg) Jupiter (r= 7.18 x 10^7 , m = 1.90 x 10^27kg) Mercury (r=2.57 x 10^6m , m= 3.28 x 10^23 kg) 2. F = mg Fg = Gm1m2 r^2 3. So i tried subbing these given masses into the second...

Wow thanks for all the help! I'm going to try redoing my questions with your advice =] I may be back for another question later tonight haha >.< Thanks again~

We were taught that for sigdigs we use the lowest amount of sigdigs in the given information as the number of sigdigs in our final answer So would I find v2 since v1 = 0 ? a = v2-v1 over time 4.o m/s^2 = v2 - 0 over 5s 20m/s = v2 therefore subbing in 5 seconds? to find the distance...

Oh okay thank you but then wouldn't i have to state the answer for part a as 3.1 x 10^2 because i cannot state 3.14? i began part b ... so... Fnetx = (4.0 x 10^2 N [E]) - 270 N [W] = 130 N F = ma 130 N = 3.2 kg (a) a = 4.06 m/s^2 a = 4.0 m/s^2

Oh sorry >.< Okay so i tried finding the friction since there is no vertical movement Fnety = 0 and Fg = mg therefore Fn = mg Fn = (32 kg)(9.81m/s^2) = 313.92 N =310 N (sigdigs) Ff = mu(Fn) =.87 x 310 = 269.7 N = 270 N [W] but i have no idea if that's accurate or not =\ i started...

1.A grocery cart has a mass of 32.0 kg. An applied force of 4.00 x 10^2 N [E] is used to move the cart. The cart starts from rest and the force is applied for 5.0s. a) Calculate the force of friction acting on the cart if the coefficient of friction between the cart and asphalt is .87 b)...