Statuc and kinetic frictional forces

In summary, a baseball player with a mass of 103kg slides into second base with a coefficient of kinetic friction of 0.607. The magnitude of the frictional force can be calculated by multiplying the coefficient by the normal force, which in this case is 103. However, this method is incorrect and the correct setup for part B is to use the equation V=Vo+At, where Vo is the initial velocity, A is the acceleration, and t is time. The frictional force should be recalculated using Fn = m*g, and then the equation can be solved for Vo. After making these adjustments, the calculated initial velocity is still incorrect for unknown reasons.
  • #1
pookisantoki
44
0
A 103kg baseball player slides into second base. Then coefficient of kinetic friction between the player and the ground is 0.607 a.) what is the magntiude of tfictional force? b.) if the player comes to rest after 2.22sec, what is his intial speed?

a.) Fs max=Ms*Fn
Ms=.607
Fn=103
0.607*103=62.521
but it's wrong
b.) I thought could use V=Vo+At
Vo=?
V=O
t=2.22
A=)Fk/m

so 0=Vo+(Fk/m)*2.22
Is this the right set up?
 
Physics news on Phys.org
  • #2
Remember that frictional force is equal to the normal force times the coefficient, not the mass.

Your method for part B seems fine, you just need to adjust your acceleration after recalculating the force of friction.
 
  • #3
0=Vo+(Fk/m)*2.22
for part b
and I set it up where
v0= -(fK/m)/2.22
Fk is .607
and m is 103
so -(.607/103)/2.22=-.002655
but its wrong what am I doing wrong. thank you
 
  • #4
Normal force Fn = m*g
 
  • #5
So i redid this problem by doing this:
Since fk=mk*Fn and Fn=m*g so (mk*m*g)/m but the m gets canceled out so...
Vo=-(Mk*g)/2.22
=(.607*9.8)/2.22
=-2.6795
But it's still wrong what am i doing wrong?
 

What is the difference between static and kinetic frictional forces?

Static frictional force refers to the force that must be overcome to set an object in motion while kinetic frictional force refers to the resistance force that acts on an object in motion. In other words, static frictional force prevents an object from moving while kinetic frictional force slows down the movement of the object.

How are static and kinetic frictional forces measured?

Static frictional force can be measured by gradually increasing the applied force on an object until it starts to move. The maximum force applied just before the object starts to move is equal to the static frictional force. On the other hand, kinetic frictional force can be measured by measuring the force required to maintain a constant speed of the object in motion.

What factors affect the magnitude of frictional forces?

The magnitude of frictional forces depends on the nature of the surfaces in contact, the normal force between the surfaces, and the roughness of the surfaces. The coefficient of friction, which is a measure of the frictional forces between two surfaces, also plays a role in determining the magnitude of frictional forces.

How do frictional forces affect the movement of objects?

Frictional forces act in the opposite direction of the movement of an object, thus causing it to slow down. This can be seen in everyday life, such as when a car's brakes are applied, the frictional force between the brake pads and the wheels causes the car to slow down and eventually stop.

Can frictional forces be reduced or eliminated?

Frictional forces cannot be completely eliminated, but they can be reduced by using lubricants between surfaces, using smoother surfaces, and reducing the normal force between the surfaces. In some cases, frictional forces can also be beneficial, such as in the case of tires on a car, which provides necessary grip and traction for safe driving.

Similar threads

  • Introductory Physics Homework Help
Replies
18
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
591
  • Introductory Physics Homework Help
Replies
1
Views
652
  • Introductory Physics Homework Help
Replies
12
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
2K
  • Introductory Physics Homework Help
Replies
33
Views
875
Back
Top