Question
\( s=u t+\frac{1}{2} a t^{2} \quad \) Solve for \( u \) given \( s=20, t=2 \) and \( a=4 \). +Workspace
Ask by Peterson Cole. in Australia
Feb 04,2025
Real Tutor Solution
Tutor-Verified Answer
Answer
\( u = 6 \) meters/second
Solution
Certainly! Let's solve for \( u \) step by step using the given equation and values.
### Given:
- Equation: \( s = u t + \frac{1}{2} a t^{2} \)
- \( s = 20 \) meters
- \( t = 2 \) seconds
- \( a = 4 \) meters/second²
### Step 1: Plug in the Known Values
Substitute the given values into the equation:
\[
20 = u \times 2 + \frac{1}{2} \times 4 \times (2)^2
\]
### Step 2: Simplify the Equation
First, calculate \( \frac{1}{2} \times 4 \times (2)^2 \):
\[
\frac{1}{2} \times 4 = 2
\]
\[
(2)^2 = 4
\]
\[
2 \times 4 = 8
\]
Now, the equation becomes:
\[
20 = 2u + 8
\]
### Step 3: Solve for \( u \)
Subtract 8 from both sides to isolate the term with \( u \):
\[
20 - 8 = 2u
\]
\[
12 = 2u
\]
Divide both sides by 2 to solve for \( u \):
\[
u = \frac{12}{2} = 6
\]
### Conclusion
The initial velocity \( u \) is **6 meters/second**.
Reviewed and approved by the UpStudy tutoring team
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The Deep Dive
To solve for \( u \), we start with the equation: \[ s = u t + \frac{1}{2} a t^{2} \] Plugging in the values \( s=20 \), \( t=2 \), and \( a=4 \): \[ 20 = u(2) + \frac{1}{2}(4)(2^2) \] Calculate \( \frac{1}{2}(4)(2^2) \): \[ \frac{1}{2}(4)(4) = 8 \] So the equation now looks like: \[ 20 = 2u + 8 \] Now, subtract 8 from both sides: \[ 20 - 8 = 2u \] This simplifies to: \[ 12 = 2u \] Now, divide both sides by 2: \[ u = \frac{12}{2} = 6 \] Thus, \( u = 6 \).