Spring constant and conservation of energy

In summary, the problem involves determining the launching speed of a ball in a pinball machine given the force constant of its spring and the angle of the surface it moves on. By using the equations for potential energy and kinetic energy, the velocity of the ball can be calculated by considering conservation of energy. The answer should be given in m/s, even though the problem does not specify units.
  • #1
Knfoster
45
0

Homework Statement


The ball launcher in a pinbgall machine has a spring that has a force constant of 36 N/cm. THe surface on which the ball moves is inclined theta=10.1 degrees with respect to the horizontal. If the spring is initially conressed 4.25 cm, find the launching speed of a .120 kg bawhen the plunger is released. Friction and the mass of the plunger e negligible.

Homework Equations



PE=.5k(xf-xi)^2
KE=.5mv^2

The Attempt at a Solution


I'not sure what launching speed is supposed to be, it supposed to be an answer that doesn't require units. Does that mean I need to be finding the spring constant? If so, do I just set the KE=PE?
 
Physics news on Phys.org
  • #2
They give you the spring constant. 36 N/cm.

So think conservation of energy.

Spring potential depressed = kinetic energy at release point plus additional increase in gravitational potential energy at release point .
 
  • #3
The force constant is the spring constant. You're looking for a velocity.

Think about it if we compress a spring at some angle we are storing potential energy in the spring, but we also have to take into account gravity, does this help?
 
  • #4
It can't be simply velocity that I'm looking for because an answer not requiring units is needed. Any other ideas?
 
  • #5
I'm pretty sure it's got units -- it asks for the launching speed. Speed's have units of distance per time.
 
  • #6
I know... it should but, I'm doing homework through lon-capa and it's telling me that it doens't require units, so it can't be asking for velocity.
 
  • #7
They ask for speed.

Calculate it as m/s.

Ignore their not asking for units.
 

1. What is the spring constant and how is it calculated?

The spring constant, also known as the force constant, is a measure of the stiffness of a spring. It is calculated by dividing the force applied to the spring by the displacement caused by the force.

2. How does the spring constant affect the behavior of a spring?

The spring constant determines how much force is needed to stretch or compress a spring. A higher spring constant means the spring is stiffer and requires more force to change its length, while a lower spring constant means the spring is more flexible and requires less force to change its length.

3. What is the relationship between the spring constant and the potential energy stored in a spring?

The potential energy stored in a spring is directly proportional to the square of the spring constant. This means that as the spring constant increases, the potential energy stored in the spring also increases.

4. How does the concept of conservation of energy apply to a spring-mass system?

The conservation of energy principle states that energy cannot be created or destroyed, only transformed from one form to another. In a spring-mass system, potential energy is converted into kinetic energy as the spring is compressed or stretched, and vice versa when the mass is released.

5. Can the spring constant change over time?

The spring constant is a characteristic of the spring itself and does not change unless the physical properties of the spring, such as its material or dimensions, are altered. However, the effective spring constant in a real-life system may appear to change due to factors such as friction, air resistance, and temperature changes.

Similar threads

Time period of SHM & Energy conservation in pulley-spring-block system
    • Introductory Physics Homework Help
Replies
24
Views
1K
Pan suspended by a spring (Energy + SHM)
    • Introductory Physics Homework Help
Replies
20
Views
2K
Spring Problem Involving Variables and Constants Only
    • Introductory Physics Homework Help
Replies
3
Views
368
Calculating spring constant of a spring loaded cannon
    • Introductory Physics Homework Help
Replies
7
Views
3K
Kinetic Energy & Momentum of a Ball released from Spring
    • Introductory Physics Homework Help
Replies
6
Views
2K
Distance of box pushed up incline by spring
    • Introductory Physics Homework Help
Replies
1
Views
2K
Graphing Kinetic Energy of a Toy Car Released from a Compressed Spring
    • Introductory Physics Homework Help
Replies
13
Views
16K
Calculating Spring Constant and Energy Conservation: How Fast Will the Bag Drop?
    • Introductory Physics Homework Help
Replies
3
Views
825
Conservation of Energy: Spring pushing a block up an incline
    • Introductory Physics Homework Help
Replies
15
Views
3K
Hooke's Law vs. Conservation of Energy
    • Introductory Physics Homework Help
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top