Coefficient of Friction/Projectile motion problem

  • Thread starter Thread starter rmiller94
  • Start date Start date
  • Tags Tags
    Coefficient Motion
AI Thread Summary
A block is projected at 3.0 m/s on a horizontal surface and comes to rest after traveling 1.5 m, prompting a calculation of the coefficient of kinetic friction. The main challenge is the absence of the block's mass, leading to confusion about how to determine the normal force. Participants suggest treating the mass as a variable 'm' to simplify calculations. The normal force can be expressed symbolically as mg, allowing for further analysis of the forces acting on the block. The discussion emphasizes the importance of understanding the relationship between friction, mass, and motion in solving the problem.
rmiller94
Messages
5
Reaction score
0

Homework Statement



A block is projected with a speed of 3.0 m/s on a horizontal surface. if the block comes to rest in 1.5 m, what is the coefficient of kinetic friction between the block and the surface?

Homework Equations



M=Ff/N
(Fapplied-Ff)=ma

I'm not really sure which equations to use for this problem since there is no mass given for the block.


The Attempt at a Solution



I really have no idea how to go about doing this problem!

I've been solving more complex friction problems but I'm currently baffled since there is no way to calculate a force, etc.
I'm taking a 12th grade physics class, by the way.
 
Physics news on Phys.org
rmiller94 said:
I'm not really sure which equations to use for this problem since there is no mass given for the block.
Maybe it doesn't matter. :wink: Just call the mass 'm' and continue. What's the force acting on the block?
 
i'm not really sure since there's no mass or weight given it seems impossible to find the normal force.

the only givens are in the problem stated above.

i'm so confused! hahah
 
rmiller94 said:
i'm not really sure since there's no mass or weight given it seems impossible to find the normal force.
Call the mass 'm'. What's the normal force? (Give it symbolically, not in terms of numbers.)
 
ooh haha i guess the normal force would just be mg?
 
rmiller94 said:
ooh haha i guess the normal force would just be mg?
Right! Keep going.
 
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

Newton's law problem: Pushing 2 stacked blocks on a horizontal table
Replies
13
Views
3K
Friction Coefficients: Determining Force Direction?
Replies
6
Views
1K
Coefficient of Friction when Normal Force is Reduced [HS]
Replies
5
Views
2K
Find the frictional force on the block
Replies
10
Views
2K
Coefficient of kinetic friction of a block sliding across the ceiling
Replies
7
Views
1K
Does coefficient of kinetic friction depend on speed?
Replies
16
Views
5K
Frictional Forces on a Wooden Crate with External Forces
Replies
1
Views
2K
What is the relationship between tension and mass in a system with friction?
Replies
6
Views
2K
Dynamics ramp and friction. Finding angle?
Replies
4
Views
2K
Two block problems with friction
Replies
6
Views
2K

Hot Threads

Recent Insights

Back
Top