Answer:
-2.0 m/s²
Explanation:Acceleration is the rate of change of velocity.
\begin{aligned}a&=\dfrac{\text{Change in velocity}}{\text{Change in time}}\\ \\ &=\dfrac{v_f-v_i}{\Delta t} \end{aligned}
a
=
Change in time
Change in velocity
=
Δt
v
f
−v
i
Hint #22 / 3
We can calculate the bicyclist's acceleration from the final velocity v_fv
f
v, start subscript, f, end subscript, initial velocity v_iv
i
v, start subscript, i, end subscript, and time interval \Delta tΔtdelta, t.
\begin{aligned}a&=\dfrac{v_f-v_i}{\Delta t}\\ \\ &=\dfrac{-21\,\dfrac{\text m}{\text s}-(-14\,\dfrac{\text m}{\text s})}{3.5\,\text s}\\ \\ &=-2.0\,\dfrac{\text m}{\text s^2}\end{aligned}
a
=
Δt
v
f
−v
i
=
3.5s
−21
s
m
−(−14
s
m
)
=−2.0
s
2
m
Hint #33 / 3
The acceleration of the bicyclist is -2.0\,\dfrac{\text m}{\text s^2}−2.0
s
2
m
minus, 2, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, squared, end fraction.