A child exerts a tangential 50.0N force on the rim of a disk-shaped merry-go-round with a radius of 2.50m. If the merry-go-round starts at rest and acquires an angular speed of 0.0800rev/s in 5.00s, what is the child's mass?
2007-10-19 15:50:55 · 6 answers · asked by Nik 1 in Science & Mathematics ➔ Physics
I need an actual number so there must be some sort of calculation to determine the mass even if the mass remains the same
2007-10-19 16:10:15 · update #1
The child travels in a circle of radius 2.5m. The perimeter of a circle is 2πr = 2π(2.5m) = 5π m.
An angular speed of 0.08 rev/s will give you a linear speed of 0.08 rev/s * 5π m. = 0.4π m/s
The acceleration is the change in speed divided by time.
(0.4π m /s )/5s = 0.08π m/s^2
F = ma
m = F/a = (50 N)/(0.08π m/s^2) = 199 kg
Either the person who wrote this is being silly or I made a mistake somewhere. That would be one very big kid. Heck, that would be a lot of mass for 3 kids.
2007-10-19 20:47:51 · answer #1 · answered by Demiurge42 7 · 0⤊ 0⤋
Centripetal Force is Defined by F(Force) = M(MASS)*A(acceleration) or F = M * (V(velocity)^2/R(radius)
You just plug in the values into the Equation
F=M(V^2/R)
50N = M( ,08Rev/s^2 / 2.5M )
(2.5M) 50N = M(.0064 Rev/s^2)
125 N*M = M(.0064 Rev/s^2)
125 N*M / (.0064 Rev/s^2) = M
M = 19531.25 Kg
2007-10-19 16:07:35 · answer #2 · answered by DP 3 · 0⤊ 2⤋
Hi. The same as at rest.
2007-10-19 15:53:20 · answer #3 · answered by Cirric 7 · 0⤊ 1⤋
Mass does not change
2007-10-19 15:58:51 · answer #4 · answered by Anonymous · 0⤊ 1⤋
Mass does not change with motion.
2007-10-19 15:54:29 · answer #5 · answered by aswkingfish 5 · 0⤊ 1⤋
Before or after he vomits?
2007-10-19 15:52:59 · answer #6 · answered by Special K 3 · 0⤊ 1⤋