Question$\text{Given:} \\
\text{Final velocity } v_f = 0.635 \, \text{m/s} \\
\text{Initial velocity } v_i = 0 \, \text{m/s} \\
\text{Mass } m = 132 \, \text{g} = 0.132 \, \text{kg} \\
\text{Change in distance } \Delta d = 98 \, \text{cm} = 0.98 \, \text{m} \\
\text{Solve for the force of friction } F_f \text{ in two different ways:} \\
\text{1. Using motion:} \\
\text{Use the kinematic equation:} \\
v_f^2 = v_i^2 + 2a\Delta d \\
\text{Solve for acceleration } a \text{ and use } F = ma \text{ to find } F_f. \\
\text{2. Using work/energy/power:} \\
\text{Use the work-energy principle:} \\
\text{Work done by friction } = \Delta \text{Kinetic Energy} \\
\text{Calculate the change in kinetic energy and equate it to the work done by friction to find } F_f.$
Studdy Solution
STEP 1
1. The motion occurs in a straight line.
2. The friction force is constant throughout the motion.
3. There are no other forces acting on the object besides friction.
4. The surface is horizontal (no incline).
5. Air resistance is negligible.
STEP 2
1. Solve for friction force using motion equations.
2. Solve for friction force using work-energy principle.
3. Compare the results.
STEP 3
Let's start by using the motion equations to solve for the friction force.
We'll use the kinematic equation:
Substituting the known values:
STEP 4
Simplify and solve for acceleration:
Now that we have the acceleration, we can use Newton's Second Law to find the friction force:
STEP 5
Now let's solve for the friction force using the work-energy principle.
The work-energy principle states that the work done by friction equals the change in kinetic energy:
Let's calculate the right side of the equation first:
STEP 6
Now we can equate this to the work done by friction:
Solving for F_f:
STEP 7
Comparing the results:
1. Using motion equations: F_f = 0.02715 N
2. Using work-energy principle: F_f = 0.02715 N
Both methods yield the same result, confirming our calculations.
The friction force is 0.02715 N.
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