ok so ike we did this experiment when u have to watch the shadow of a circle until it moves a complete diameter. the time we got was 3:37 (minutes). and were supposed to assume that the moving one diameter is equal to .5 degrees.
the formula were supposed to use is time/.5 degrees x 360 degrees/1 rotation.
we ended up with 43.4. is that right? what did we do wrong?
and for linear speed, the equation is d/t = 2pi r /hours. the earth to sun distance is 149.6 x10 exponent 6 km. raduis of the earth is 638 x 10 exponent 3 km.
does anyone know how to do this?
thankkkss sooo much if u do.
2007-09-12 18:12:09 · 3 answers · asked by nikijoe46 3 in Science & Mathematics ➔ Physics
43.4 hr is correct.
Time for 1 rev = 3.617 min * 360 d / 0.5 d = 3.617*720 = 2604 min = 43.4 hr
This is longer than a day which = 24 hr, so the assumption is wrong or the measured time was wrong.
The linear speed you refer to, if t is the same time as your measured time, is the speed of the spinning earth at its equator. To get this speed v you use the radius of the earth r in the formula v = 2*pi*r/hours where hours is the 43.4 hr "day length" result of the measured time. Thus v = 2*pi*6.38^10^3/43.4 = 924 km/hr. But since we know that hours really = 24, a better answer is 2*pi*6.38^10^3/24 = 1670 km/hr.
2007-09-16 03:03:37 · answer #1 · answered by kirchwey 7 · 0⤊ 0⤋
w = v*r the place w = angular velocity, v = linear velocity The radius of the rotation isn't the radius of the earth regardless of the undeniable fact that. feels like this merchandise is on a style line above the equator. The radius could be R = radius of earth if the perspective with the axis have been ninety levels. fairly that's R*sin(sixty 9 deg) a = v^2/r = w^2 * r
2016-12-16 18:51:18 · answer #2 · answered by ? 4 · 0⤊ 0⤋
I don't have a very good answer for you. I'm not quite clear on your set-up: I wonder if there might be something that depends on your latitude that you haven't taken properly into account.
Anyway, here are some standard instructions on building sundials: Maybe if you look them over, you can see something that your teacher forgot to mention.
Good luck, nikkijoe46. At least someone here is trying to do something more than get their homework questions answered for them.
2007-09-16 03:10:51 · answer #3 · answered by ? 6 · 0⤊ 0⤋