Math Problem Statement

The graph of acceleration (on the vertical axis) versus time (on the horizontal axis) is a horizontal line given by ax = 2.0 m/s2 from 0 seconds to 4 seconds and very quickly changes to a horizontal line given by ax = -- 3.0 m/s2 from 4 seconds to 7 seconds. Find the change in velocity from time equals 1 second to time equals 5 seconds.

Multiple choice question.

Solution

To find the change in velocity from time t=1t = 1 second to t=5t = 5 seconds, we need to use the relationship between acceleration and velocity. The change in velocity (Δv\Delta v) can be found by integrating the acceleration over the given time interval:

Δv=t1t2a(t)dt\Delta v = \int_{t_1}^{t_2} a(t) \, dt

Given:

  • From t=0t = 0 s to t=4t = 4 s, acceleration a(t)=2.0m/s2a(t) = 2.0 \, \text{m/s}^2.
  • From t=4t = 4 s to t=7t = 7 s, acceleration a(t)=3.0m/s2a(t) = -3.0 \, \text{m/s}^2.

We need to find the change in velocity from t=1t = 1 second to t=5t = 5 seconds.

Steps:

  1. Calculate the change in velocity from t=1t = 1 s to t=4t = 4 s: Δv1=142.0dt=2.0×(41)=2.0×3=6.0m/s\Delta v_1 = \int_{1}^{4} 2.0 \, dt = 2.0 \times (4 - 1) = 2.0 \times 3 = 6.0 \, \text{m/s}

  2. Calculate the change in velocity from t=4t = 4 s to t=5t = 5 s: Δv2=453.0dt=3.0×(54)=3.0×1=3.0m/s\Delta v_2 = \int_{4}^{5} -3.0 \, dt = -3.0 \times (5 - 4) = -3.0 \times 1 = -3.0 \, \text{m/s}

  3. Add the changes in velocity: Δv=Δv1+Δv2=6.0m/s+(3.0m/s)=3.0m/s\Delta v = \Delta v_1 + \Delta v_2 = 6.0 \, \text{m/s} + (-3.0 \, \text{m/s}) = 3.0 \, \text{m/s}

Answer:

The change in velocity from t=1t = 1 second to t=5t = 5 seconds is 3.0 m/s.

Would you like more details, or do you have any other questions?

Related Questions:

  1. How do you calculate displacement from a velocity-time graph?
  2. What is the significance of the area under the curve in acceleration-time graphs?
  3. Can you explain the relationship between acceleration, velocity, and displacement?
  4. How do initial conditions affect the calculation of velocity from acceleration?
  5. How would the problem change if acceleration were a function of time rather than a constant?

Tip:

When analyzing motion using acceleration-time graphs, remember that the area under the curve between two time intervals gives you the change in velocity over that period.

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Math Problem Analysis

Mathematical Concepts

Calculus
Kinematics

Formulas

Integral of acceleration to find velocity

Theorems

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Suitable Grade Level

High School