Numerical Problem: Motion in One Dimension
To solve a numerical problem related to motion in one dimension, follow these steps:
Step 1: Understand the Problem
Read the problem carefully and identify the given information and what needs to be calculated. Draw a diagram if necessary.
Step 2: Determine the Relevant Equations
Identify the equations that can be used to solve the problem. The equations for motion in one dimension are:
- v = u + at
- s = ut + 0.5at^2
- v^2 = u^2 + 2as
where v is final velocity, u is initial velocity, a is acceleration, t is time, and s is displacement.
Step 3: Solve the Problem
Substitute the given values into the relevant equation(s) and solve for the unknown(s). Make sure to use the correct units and round off the answer to the appropriate number of significant figures.
Step 4: Check the Answer
Check the answer to make sure it makes sense and is reasonable. If possible, check the answer using a different method or by estimating the answer.
Example Problem:
A car accelerates from rest at a rate of 4 m/s^2 for 10 seconds. What is its final velocity and displacement?
Solution:
Step 1: Understand the Problem
Given: u = 0 m/s, a = 4 m/s^2, t = 10 s
Unknown: v, s
Step 2: Determine the Relevant Equations
The relevant equations are:
- v = u + at
- s = ut + 0.5at^2
Step 3: Solve the Problem
Using the first equation:
v = u + at
v = 0 + 4(10)
v = 40 m/s
Using the second equation:
s = ut + 0.5at^2
s = 0(10) + 0.5(4)(10)^2
s = 200 m
Step 4: Check the Answer
The answer for the final velocity is 40 m/s, which is reasonable since the car has been accelerating for 10 seconds. The answer for the displacement is 200 m, which is also reasonable since the car has been accelerating for 10 seconds at a constant rate.