Kinematics Equations Video Lessons

Concept

# Problem: The head of a rattlesnake can accelerate at 50m/s2 in striking a victim. If a car could do as well, how long would it take to reach a speed of 100km/h from rest?

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###### FREE Expert Solution

For this problem, we're asked to find the time taken by an accelerating object to reach target speed.

When solving problems with uniformly accelerated motion (UAM), Step Zero is making sure that the acceleration is constantotherwise, our kinematics equations don’t apply. Then we'll follow these steps to solve the problem:

1. Identify the target, known and unknown variables for each part of the problem—remember that only 3 of the 5 variablesx, v0, vf, a, and t) are needed to solve any kinematics problem.
2. Choose a UAM equation with only one unknown, which should be our target variable.
3. Solve the equation for the target variable, then substitute known values and calculate the answer.

The four UAM (kinematics) equations are:

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###### Problem Details

The head of a rattlesnake can accelerate at 50m/s2 in striking a victim. If a car could do as well, how long would it take to reach a speed of 100km/h from rest?