Need help with potential energy, kinetic energy ect.

AI Thread Summary
The discussion centers on understanding potential and kinetic energy concepts related to a homework assignment. To find the potential energy stored in an elastic band, the formula used is work done, calculated as force multiplied by distance. The energy transferred to an object when the elastic is released is equal to the stored potential energy. The kinetic energy of the object can be determined using the formula 1/2 (mv^2), and the height the object will rise can be calculated using the equation h = v^2/(2g). A recommendation is made to review the relevant theories and formulas before attempting to solve the problems.
Justinfrank
Messages
1
Reaction score
0
I have home work that I cannot understand, it relates to kinetic energy, and energy potential I cannot find the formula to use to solve it

Heres some of the questions

1.An elastic band is stretched a distance of 15.0cm by a force of 10.0N

A.How much potential energy is stored in the elastic.- I don't understand how to find that out.

2. A 1.00 g object is placed on the elastic, and the elastic is released in a vertical direction. How much energy was transferred to the object by the elastic? Can't figure out how to solve.

A.What was the speed of the object as it leaves the elastic? Don't know the formula

B.How high will the object rise (assume no friction)- Don't know the formula

Please help me solve these questions as this assignment is due tommorow.

And sorry I couldn't show any work I've done, because I cannot figure out where to start with these
questions.
 
Last edited:
Physics news on Phys.org
hello Justin, welcome to PF!

for no. 1, work done = potential energy stored. so work done is Force x distance (use SI units)
 
in no. 2, energy stored in elastic is transferred to object, so it is same value.

3. formula for kinetic energy is 1/2 (mv^2). i suggest you first go through the theory and learn the formulas before solving problems.
 
use equations of motion for last one. using it you will have

h = v^2/(2g)
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Conservation of Momentum Problem - Mechanical and Kinetic Energies
Replies
2
Views
955
Conservation of Energy with Gravitational Potential Energy
Replies
6
Views
2K
Confused about a conservation of energy problem
Replies
4
Views
2K
Expression for magnitude of the constant friction force
Replies
7
Views
1K
Kinetic & Potential Energy of a Pendulum
Replies
3
Views
2K
Challenging problem about an impact with a smooth frictionless surface
2
Replies
55
Views
5K
Calculating Kinetic & Potential Energy: Is it Correct?
Replies
12
Views
1K
Why is the elastic potential energy in position 2 zero?
Replies
6
Views
2K
Minimal rotational kinetic energy for a gyroscope to precess
Replies
33
Views
2K
Catapult spring, Kinetic and Potential energy
Replies
10
Views
3K

Hot Threads

Recent Insights

Back
Top