116k views
3 votes
A car suspension can undergo a maximum displacement of about an additional 6 cm from its resting position when inside a car before breaking. The mass of the car is roughly 2000kg and the car suspension has an initial displacement of 8.5 cm from its equilibrium position, while the maximum force exerted on the car in the vertical direction is an additional 1.4x104 N before the spring breaks. Determine the change in elastic potential energy of the suspension between the maximum force before the spring breaks and when no additional force is being exerted on the care beside the Earth. State all of you assumptions here explicitly.

User NPS
by
8.1k points

1 Answer

4 votes

Answer: The change in elastic potential energy is 3,045 J.

Explanation: The change in elastic potential energy of the suspension between the maximum force before the spring breaks and when no additional force is being exerted on the car beside the Earth can be calculated using the formula:

ΔPE = 1/2k(x2^2 - x1^2)

where ΔPE is the change in elastic potential energy, k is the spring constant, x1 is the initial displacement of the suspension from its equilibrium position, and x2 is the maximum displacement of the suspension from its equilibrium position.

Assuming that the spring follows Hooke’s law, which states that the force exerted by a spring is proportional to its displacement from its equilibrium position, we can calculate the spring constant using:

k = F/x

where F is the maximum force exerted on the car in the vertical direction and x is the maximum displacement of the suspension from its equilibrium position.

Using these formulas and given that the mass of the car is roughly 2000kg and that the car suspension has an initial displacement of 8.5 cm from its equilibrium position, we can calculate that:

x2 = 8.5 cm + 6 cm = 14.5 cm

x1 = 8.5 cm

x = 14.5 cm - 8.5 cm = 6 cm

F = 1.4x10^4 N

k = F/x = (1.4x10^4 N) / (6 cm) = 2.33x10^5 N/m

ΔPE = 1/2k(x2^2 - x1^2) = (0.5)(2.33x10^5 N/m)((0.145 m)^2 - (0.085 m)^2) = 3,045 J

Therefore, the change in elastic potential energy of the suspension between the maximum force before the spring breaks and when no additional force is being exerted on the car beside Earth is 3,045 J.

Hope this helps, and have a great day!

User Terra Kestrel
by
8.6k points