A cyclist travels at a constant velocity of 4.5 m/s westward, then speeds up with a steady acceleration of 2.3m/s2. Calculate the cyclist’s speed after accelerating for 5.0 s.
To find the cyclist's speed after accelerating, we can use the formula for final velocity:
\[
v_f = v_i + a \cdot t
\]
where:
- \( v_f \) is the final velocity,
- \( v_i \) is the initial velocity,
- \( a \) is the acceleration,
- \( t \) is the time.
Given:
- \( v_i = 4.5 \, \text{m/s} \) (initial velocity, westward),
- \( a = 2.3 \, \text{m/s}^2 \) (acceleration),
- \( t = 5.0 \, \text{s} \) (time).
Substituting the values into the formula:
\[
v_f = 4.5 \, \text{m/s} + (2.3 \, \text{m/s}^2 \cdot 5.0 \, \text{s})
\]
Calculating the acceleration distance:
\[
2.3 \, \text{m/s}^2 \cdot 5.0 \, \text{s} = 11.5 \, \text{m/s}
\]
Now adding that to the initial velocity:
\[
v_f = 4.5 \, \text{m/s} + 11.5 \, \text{m/s} = 16.0 \, \text{m/s}
\]
So, the cyclist's speed after accelerating for 5.0 seconds is:
\[
\boxed{16.0 \, \text{m/s}}
\] (still moving westward).