Physics, Kinematics (6 of 7) 1 D Horizontal Motion, Solve for Time, No. 1

TL;DR

This video explains how to solve kinematic equations for one-dimensional horizontal motion, using two example problems.

Transcript

okay in today's video I'm going to go over two problems using the kinematic equation for one-dimensional horizontal motion and in both of the examples that I'm going to do in this video we're going to be solving for the time here's our first problem we have a starting from rest a Pro Stock race car can complete a quarter mile that's about 400 m wit... Read More

Key Insights

• 😣 The initial velocity is zero in both problems, indicating that the objects start from rest.
• ⌛ The time can be solved using the equation Δx = Vi * t + (1/2) * a * t^2.
• ⌛ The acceleration is not needed to solve for the time in either problem.
• ❓ It is important to carefully choose the appropriate kinematic equation that contains the variable being solved for.
• ⌛ The final velocity is not always necessary to find the time in kinematic problems.
• 😀 The time required for the race car to complete the quarter mile is 10.95 seconds.
• 😀 The top fuel drag racer completes the quarter mile in 5.97 seconds.

Questions & Answers

Q: What are the five variables involved in kinematic equations?

The five variables are initial velocity, final velocity, change in position (distance), acceleration, and time.

Q: Why is the final velocity ignored in the first problem?

The final velocity is ignored because the problem only asks for the time it takes to complete the quarter mile, not the final velocity.

Q: How do you determine which kinematic equation to use?

Look for an equation that contains the variable you are trying to find (in this case, time) and has the other three known variables.

Q: What is the equation used to solve the second problem?

The equation used is Δx = (Vf + Vi) * t / 2, where Δx is the distance, Vf is the final velocity, Vi is the initial velocity, and t is the time.

Summary & Key Takeaways

• The video demonstrates how to solve for the time it takes for a Pro Stock race car to complete a quarter mile, given its average acceleration.

• The second problem involves finding the time it takes for a top fuel drag racer to complete a quarter mile, starting from rest and having a top speed of 134 m/s.