Physics
posted by Susan
I need help with part b, c, and d please!
A 45 g mass is attached to a massless spring and allowed to oscillate around an equilibrium according to:
y(t) = 1.4 * sin( 4 * t ) where y is measured in meters and t in seconds.

(a) What is the spring constant in N/m?
k = N/m *
0.72 OK
HELP: You are given m, the mass. What other quantity appears in the equation involving k, the spring constant, and m?
HELP: You are given the equation of motion
y(t) = A * sin( ù * t )
Now can you find the missing quantity?
HELP: Be careful of the units of m.

(b) What is the Total Energy in the mass and spring in J?
E = J
HELP: The total energy is the sum of the kinetic energy and potential energy. At what point in the motion is the energy all kinetic? At what point is it all potential? Can you compute it at this point?
HELP: Kinetic energy is 1/2 * Mass * v2
Potential energy is 1/2 * k * y2
We know that at the mass's maximum yposition it has zero velocity, so simply compute Potential Energy at that point.

(c) What is the maximum Kinetic Energy of the mass?
KE = J
HELP: Remember that Total Energy = Kinetic + Potential Energy.
HELP: When the mass is at y=0, it has zero potential energy. So what must its kinetic energy be at that point?

(d) What is the maximum velocity of the mass in m/s ?
v(max) = m/s
HELP: Maximum velocity occurs at maximum kinetic energy.
HELP: KE = 1/2 * Mass * v2
Solve for v using the result from part (c).

Kristin
for part b, take the amplitude (1.4) and square it and then multiply by what you got for part a.
so PE = .5 * k * x^2
= .5 * .72 * 1.4^2 
Kristin
for part c, the answer should be the exact same as part b.

Kristin
and for part d, take what the answer you got for c and plug all your variables into the equation of
answer part c = .5 * .045 * v^2
Respond to this Question
Similar Questions

physics
when a mass attached to a spring is released from rest 3.0 cm from its equilibrium position, it oscillates with a frequency f. If this mass were instead released from rest 6.0 cm from its equilibrium position, it would oscillate with … 
Physics
I need help with b... I found that k=.750880 for part a but I can't figure out what y would be to get potential energy. A 52 g mass is attached to a massless spring and allowed to oscillate around an equilibrium according to: y(t) … 
Physics
A 45 g mass is attached to a massless spring and allowed to oscillate around an equilibrium according to: y(t) = 1.3 * sin( 0.6 * t ) where y is measured in meters and t in seconds. (a) What is the spring constant in N/m? 
physics
A 45 g mass is attached to a massless spring and allowed to oscillate around an equilibrium according to: y(t) = 1.3 * sin( 0.6 * t ) where y is measured in meters and t in seconds. (a) What is the spring constant in N/m? 
physics
A 45 g mass is attached to a massless spring and allowed to oscillate around an equilibrium according to: y(t) = 1.3 * sin( 0.6 * t ) where y is measured in meters and t in seconds. (a) What is the spring constant in N/m? 
physics
A 45 g mass is attached to a massless spring and allowed to oscillate around an equilibrium according to: y(t) = 1.3 * sin( 0.6 * t ) where y is measured in meters and t in seconds. (a) What is the spring constant in N/m? 
Physics Help!
A 2.2 kg mass is attached to a spring with a force constant of 560 N/m on a smooth horizontal surface. The mass is pulled to one side, released, and allowed to oscillate back and forth. (a) find the maximum compression and expansion … 
physics please help!!
Hung vertically, a massless spring extends by 3.00 cm when a mass of 992.0 g is attached to its lower end. The same mass and spring are then placed apart on a table. The spring is fixed in place and then the mass is given a velocity … 
Physics
A spring, (spring constant of 400 N/m) is displaced .75 m from its equilibrium position. An 8kg mass is connected to the spring and it is allowed to oscillate horizontally with Simple Harmonic Motion. What is the Kinetic Energy of … 
Physics
A massless spring, with K=425 N/m, is hung vertically with the bottom end of the spring at position Y.i. A 3.50 kg mass is attached to the bottom of the spring and allowed to fall and oscillate. A) How far below Y.i does the mass fall …