Math Problem Statement

A rocket model has a maximum speed at the time of 29.5 m/s after a 1.7 s launch, where the acceleration is 37.4 m/s². Find the velocity just before the rocket hits the ground. Identify the given variables.

Solution

The text in the image reads:

"A rocket model has a maximum speed at the time of 29.5 m/s after a 1.7 s launch, where the acceleration is 37.4 m/s². Find the velocity just before the rocket hits the ground. Identify the given variables."

Solution Outline:

  1. Given Variables:

    • Maximum speed (v_max) = 29.5 m/s
    • Time of launch (t) = 1.7 s
    • Acceleration (a) = 37.4 m/s²
  2. Find:

    • The velocity just before the rocket hits the ground (v_final).

Solution:

The problem can be divided into two parts:

  1. Ascent - The rocket rises until it reaches the maximum height.
  2. Descent - The rocket falls back to the ground.

However, since the maximum speed is given at a particular time and acceleration, we use this information to calculate the height reached.

Step 1: Calculate the height (h) at maximum speed.

v=u+atv = u + at Where:

  • uu = Initial velocity (which we assume to be 0 since it's a model rocket starting from rest),
  • aa = Acceleration,
  • tt = Time.

So, vmax=0+(37.4m/s2)×1.7sv_{max} = 0 + (37.4 \, \text{m/s}^2) \times 1.7 \, \text{s} vmax=63.58m/sv_{max} = 63.58 \, \text{m/s}

But this is higher than the given maximum speed (29.5 m/s). So it seems the rocket stops accelerating after a certain time. We correct our previous approach:

Since we have the maximum speed, we don't need to calculate height for now. Instead, the final velocity before hitting the ground will be the same as the maximum velocity (ignoring air resistance and assuming it falls back symmetrically).

Final Answer:

The velocity just before the rocket hits the ground is v=29.5m/sv = 29.5 \, \text{m/s}.

Would you like further details or have any questions?


Relative Questions:

  1. How does the symmetry of projectile motion affect the final velocity calculation?
  2. What would happen if we included air resistance in the calculations?
  3. How do we calculate the maximum height reached by the rocket?
  4. What is the significance of acceleration in the launch phase?
  5. How can we determine the time taken to fall back to the ground?

Tip: Always check if the conditions in a problem allow you to simplify calculations, such as using symmetry in projectile motion.

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Math Problem Analysis

Mathematical Concepts

Kinematics
Projectile Motion
Symmetry in Motion

Formulas

v = u + at
v_final = v_max (due to symmetry)

Theorems

Symmetry in projectile motion (final velocity equals the velocity at maximum height)

Suitable Grade Level

Grades 9-12