Should I use the Universal Law of Gravitation instead?
F = GmM/r^2
Still not sure what to do then? I feel like I am making this problem harder than it really is.
(a) At what height above the Earth is the acceleration due to gravity 10% of its value at the surface?
(b) What is the speed of a satellite orbiting at that height?
Note: _e means earth
g = { g_e / [1+(h/R_e)^2] }
At height 0, g = 9.83m/s^2
R = 6400km
I know that we need to...
A 0.5kg steel block rotates on a steel table while attached to a 1.2meter long hollow tube. Compressed air fed through the tub and ejected from a nozzle on the back of the block exerts thrust force of 4.0N perpendicular to the tube. The maximum tension the tub can withstand without breaking is...
A boy ties a 500kg rock to a 1.0m long string and swings it around his head in a horizontal circle. At what angular velocity, in rpm, does the string tilt down at a 10 degree angle?
sintheta = mg / T
sin10 = 0.5kg(9.8m/s^2) / T
T = 4.9N / sin10
T = 28.22N
THEN...
v = SqRt...
It seems like something is off for my x-componenet.
F_x=ma_x
-f_k - Fgcostheta = ma_x
-f_k - mgcostheta = ma_x
-u_kn - mgcostheta = ma_x Substitute mgsintheta in for "n" which is the y comp.
-u_k * mgsintheta - mgcostheta = ma_x u is really mu but I am writing it as "u" to simplify...
FED EX:
You equation actually worked if you just cancel out all the m's and then plug and chug.
g sintheta - mu g costheta = a
9.8sin20 - 0.5(9.8)cos20 = a
3.35 - 4.604 = a
a = - 1.25
Now plug this into the Kinematic equation
V_f^2 = V_i^2 + 2ad
0 = V_i^2 + 2(-1.25)(3.5)...
No other INFO.
I think it is just assumed that the boy falls exactly parallel to the 20 degree slope and instantly starts sliding.
There is no info that states the boy's mass.
Johnny jumps off a swing, lands sitting down on a grassy 20 degree slope, and slides 3.5 meters down the slope before stopping. The coefficient of kinetic friction between grass and the seat of Johnny's pants is 0.5. What was his intial speed on the grass?
I started to do this problem on my...