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Grade 11General Physics

In Figure P4.53, the coefficient of kinetic friction between the two blocks shown is 0.26. The surface of the table and the pulleys are frictionless.Figure P4.53(a) Draw a free-body diagram for each block. (Do this on paper. Your instructor may ask you to turn in this work.)(b) Determine the magnitude of the acceleration of each block. 2 kg block 122.908Your response differs from the correct answer by more than 100%. m/s2 3 kg block 2Your response differs from the correct answer by more than 10%. Double check your calculations. m/s2 10 kg block 3Your response differs from the correct answer by more than 10%. Double check your calculations. m/s2 (c) Find the tension in the strings. T1 4Your response differs from the correct answer by more than 10%. Double check your calculations. N T2 5 N Hint: Active Figure 4.18

Profile image of Radhika Batra
12 Years agoGrade 11
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1 Answer

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ApprovedApproved Tutor Answer1 Year ago

To tackle the problem involving the two blocks and the coefficient of kinetic friction, we need to break it down into manageable parts. Let's first discuss how to draw the free-body diagrams for each block, then we'll calculate the acceleration and the tension in the strings.

Free-Body Diagrams

When drawing free-body diagrams, it's essential to identify all the forces acting on each block. For this scenario, we have two blocks: a 2 kg block and a 3 kg block, with a coefficient of kinetic friction of 0.26. Here’s how to approach it:

  • 2 kg Block:
    • Weight (W1) acting downwards: W1 = m1 * g = 2 kg * 9.81 m/s² = 19.62 N
    • Normal force (N1) acting upwards, equal to W1 since it’s on a horizontal surface.
    • Tension (T1) acting horizontally to the right.
    • Frictional force (f1) acting to the left: f1 = μ * N1 = 0.26 * 19.62 N = 5.1 N.
  • 3 kg Block:
    • Weight (W2) acting downwards: W2 = m2 * g = 3 kg * 9.81 m/s² = 29.43 N.
    • Normal force (N2) acting upwards, equal to W2.
    • Tension (T2) acting upwards.

Calculating Acceleration

Next, we need to determine the acceleration of each block. We can use Newton's second law, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration (F = ma).

For the 2 kg Block:

The net force (F_net1) acting on the 2 kg block can be expressed as:

F_net1 = T1 - f1

Substituting the values we have:

F_net1 = T1 - 5.1 N

According to Newton's second law:

T1 - 5.1 N = 2 kg * a

Thus, we can express T1 in terms of acceleration:

T1 = 2a + 5.1 N

For the 3 kg Block:

The net force (F_net2) acting on the 3 kg block is:

F_net2 = W2 - T2

Substituting the values:

29.43 N - T2 = 3 kg * a

So, we can express T2 in terms of acceleration:

T2 = 29.43 N - 3a

Setting Up the Equations

Now we have two equations:

  • T1 = 2a + 5.1 N
  • T2 = 29.43 N - 3a

Since T1 = T2 (the tension in the strings is the same), we can set these equations equal to each other:

2a + 5.1 N = 29.43 N - 3a

Solving for Acceleration

Now, let's solve for 'a':

2a + 3a = 29.43 N - 5.1 N

5a = 24.33 N

a = 24.33 N / 5 = 4.87 m/s²

Finding Tension in the Strings

Now that we have the acceleration, we can substitute 'a' back into either equation for T1 or T2. Let's use T1:

T1 = 2(4.87 m/s²) + 5.1 N = 9.74 N + 5.1 N = 14.84 N

And for T2:

T2 = 29.43 N - 3(4.87 m/s²) = 29.43 N - 14.61 N = 14.82 N

Summary of Results

To summarize, we found:

  • Acceleration of the 2 kg block: 4.87 m/s²
  • Acceleration of the 3 kg block: 4.87 m/s²
  • Tension in the strings (T1 and T2): approximately 14.84 N

Make sure to double-check your calculations and ensure that all units are consistent. If you have any further questions or need clarification on any steps, feel free to ask!