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A man applies a constant horizontal force of 100N to a block of wood on a smooth horizontal floor. The block starts from rest and moves 12m in 5seconds. If the man stops pushing at the end of 5seconds, how far does the block move in the next 5seconds?

User Lawanda
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The block moves 24 meters in the next 5 seconds after the man stops pushing.

The motion of the block can be analyzed using Newton's second law and the equations of motion.

1. **Determine Acceleration (a):**

Using Newton's second law \( F = ma \), where \( F \) is the force, \( m \) is the mass, and \( a \) is the acceleration. In this case, the applied force is 100 N.

\[ a = \frac{F}{m} \]

2. **Determine Initial Velocity (u):**

The block starts from rest, so the initial velocity \( u \) is 0 m/s.

3. **Use Equations of Motion:**

Using the equation of motion \( s = ut + \frac{1}{2}at^2 \), where \( s \) is the displacement, \( u \) is the initial velocity, \( a \) is the acceleration, and \( t \) is the time.

- **First 5 Seconds:**

\[ s_1 = ut_1 + \frac{1}{2}a(t_1)^2 \]

Substituting the given values:

\[ s_1 = 0 \times 5 + \frac{1}{2}a(5)^2 \]

Solving for \( a \):

\[ 12 = \frac{1}{2}a(5)^2 \]

\[ a = \frac{12 \times 2}{5^2} \]

\[ a = \frac{24}{25} \, \text{m/s}^2 \]

Now that we have \( a \), we can find \( s_1 \) during the first 5 seconds.

- **Next 5 Seconds:**

The man stops pushing, so there is no force applied. The block moves with its acquired velocity from the first 5 seconds.

\[ v = u + at \]

\[ v = 0 + \frac{24}{25} \times 5 \]

Now, use \( s = ut + \frac{1}{2}at^2 \) again to find the displacement during the next 5 seconds.

\[ s_2 = ut_2 + \frac{1}{2}a(t_2)^2 \]

Substituting the values:

\[ s_2 = \frac{24}{25} \times 5 \times 5 + \frac{1}{2} \times 0 \times (5)^2 \]

Simplifying:

\[ s_2 = \frac{600}{25} \]

\[ s_2 = 24 \, \text{m} \]

**Result:**

The block moves 24 meters in the next 5 seconds after the man stops pushing.

User Martin Hennings
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