Initial kinetic energy homework

AI Thread Summary
The homework problem involves calculating the distance an object will travel before stopping, given its initial kinetic energy of 20 Joules and a frictional force of 4 N acting against it. The discussion highlights confusion about the definition of work and its relationship to power, with participants noting that work is typically defined in terms of force and distance. The relevant equations for solving the problem include the work-energy principle, which connects kinetic energy and work done by friction. Clarification on these concepts is needed to progress with the solution. Understanding the relationship between work, force, and distance is crucial for solving the problem effectively.
lindzpooh
Messages
7
Reaction score
0
super lost!

Homework Statement


a moving object whose initial kinetic energy is 20 Joules is subject to a frictional force of 4 N that acts in the opposite directon. how far will the object move before coming to a stop.


Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
Oh super...

What is the definition of work?
 
work p=w/t
 
you sure?

P is power, I believe. (I'm not that far in physics yet, but I am in the work section.) :)

Should be something involving these variables: W, F, and s.
 
Last edited:
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 »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Resistance force changing the velocity of an object
Replies
8
Views
1K
Friction and an object stopping
Replies
12
Views
3K
Minimal rotational kinetic energy for a gyroscope to precess
Replies
33
Views
2K
Work done during a collision -- Change in Kinetic Energy & change in Momentum
Replies
1
Views
2K
Solving the Platform and Object Kinetic Energy Equation
Replies
8
Views
2K
Kinetic Energy and Newton Forces - distance/speed
Replies
3
Views
2K
Initial and Final Kinetic Energy
Replies
1
Views
2K
Kinetic energy as seen from a different frame
Replies
16
Views
2K
Conservation of Energy with changing masses on ice
Replies
2
Views
1K
What Was the Initial Speed of the Proton in a Collision?
Replies
2
Views
3K

Hot Threads

Recent Insights

Back
Top