Need Help - Regarding the mixture of circular motion and hooke's law

[Lolagoeslala]

Homework Statement

A 1.01 kg mass is attached to a spring of force constant 9.5 N/cm and placed on a frictionless surface. By how much will the spring stretch if the mass moves along a circular path of radius 0.485 m at a rate of 2.14 revolutions per second?

What i was thinking was using the following equation:
Fc= Kx - mg
Which would turn into
a=kx-g
(4pi^2(R)(F)^2 +g)/K=x

 

[ehild]

Homework Statement

A 1.01 kg mass is attached to a spring of force constant 9.5 N/cm and placed on a frictionless surface. By how much will the spring stretch if the mass moves along a circular path of radius 0.485 m at a rate of 2.14 revolutions per second?

What i was thinking was using the following equation:
Fc= Kx - mg
Which would turn into
a=kx-g
(4pi^2(R)(F)^2 +g)/K=x

Is it a horizontal surface the mass moves on?

ehild

 

[Lolagoeslala]

Is it a horizontal surface the mass moves on?

ehild

It does not state...

 

[ehild]

I guess the surfaceis horizontal, the angle of inclination would be stated otherwise. So the only force in the plane of motion is the force of the spring. Gravity cancels with the normal force of the surface.

ehild

 

[Lolagoeslala]

I guess the surfaceis horizontal, the angle of inclination would be stated otherwise. So the only force in the plane of motion is the force of the spring. Gravity cancels with the normal force of the surface.

ehild

Would u like to show me that using the equation...
Kx=Mg somewhere you also need to include the acceleration i guess

 

[ehild]

Mg is a vertical force. The object moves horizontally, along a circle. What force is needed to make it move along that circle of radius 0.485 m with 2.14 revolutions per second?

ehild

 

[Lolagoeslala]

Mg is a vertical force. The object moves horizontally, along a circle. What force is needed to make it move along that circle of radius 0.485 m with 2.14 revolutions per second?

ehild

m= 1.01 kg
K= 9.5 N/cm = 950 N/m
r= 0.485 m
f= 2.14 Hz

Kx= ma
kx= m x 4pi^2 x r x f^2
950 N/mx = 88.472 N
x= 0.0931 m

 

[ehild]

Your solution is correct.

ehild