A hockey puck slides with an initial speed of 52.3 m/s on a large frozen lake. If the coefficient of kinetic friction between the puck and the ice is 0.02, what is the speed of the puck after 11.8 s?
vf=vi+at
but a=- force/mass=-mu*mg/m=-mu*g
the negative sign indicates oposite direction to movement
solve for Vf
To find the speed of the puck after 11.8 seconds, we need to consider the forces acting on the puck and apply Newton's laws of motion.
The first step is to determine the acceleration of the puck caused by friction. The force of kinetic friction can be calculated using the formula:
Friction force (Fk) = coefficient of kinetic friction (μk) * normal force (N)
The normal force, in this case, is equal to the weight of the puck since it is on a flat surface. The weight (W) is given by:
Weight (W) = mass (m) * gravity (g)
Now, we can calculate the friction force using the given values. Let's assume the mass of the puck is m.
Next, we will calculate the acceleration using Newton's second law of motion, which states that the net force on an object is equal to the product of its mass and acceleration:
Net force (Fnet) = mass (m) * acceleration (a)
In this case, the net force is equal to the force due to friction (Fk) because there are no other horizontal forces acting on the puck. Therefore:
Fk = m * a
Now, we can calculate the acceleration (a) using the known values: the friction force (Fk) and the mass (m).
Once we have the acceleration, we can find the final velocity (vf) using the following equation of motion:
vf = vi + a * t
where:
vi is the initial velocity (given as 52.3 m/s),
a is the acceleration (calculated previously),
t is the time (given as 11.8 s).
Substitute the given and calculated values into the equation to find the final velocity (vf).