Acceleration = (change in speed)/(time for the change)
Change in speed = (end speed) - (start speed)
Change in speed = (10 m/s) - (20 m/s) = -10 m/s
Time for the change = 5.00 seconds
Acceleration = (-10 m/s) / (5 sec)
Acceleration = -2 m/s²
That's choice-A .
Hello!
A car going 72.0 km/h (20.0 m/s) slows down to 36.0 km/h (10.0 m/s) in 5.00 seconds. Calculate the acceleration in m/s² .
We have the following data:
a (acceleration) = ? (in m/s²)
Vi (initial velocity) = 20 m/s
Vf (final velocity) = 10 m/s
Δv (velocity variation) = Vf - Vi , then:
[tex]\Delta{V} = V_f - V_i[/tex]
[tex]\Delta{V} = 10 - 20[/tex]
[tex]\Delta{V} = - 10\:m/s[/tex]
Δt (time variation) = 5 s
We apply the data to the average acceleration formula, see:
[tex]a = \dfrac{\Delta{V}}{\Delta{T}}[/tex]
[tex]a = \dfrac{- 10\:\dfrac{m}{s} }{5\:s}[/tex]
[tex]\boxed{\boxed{a = - 2\:\dfrac{m}{s^2} }}\end{array}}\qquad\checkmark[/tex]
Answer:
A. -2.00
_______________________________
I Hope this helps, greetings ... Dexteright02! =)
