A person needs to reach 120km/hr on an 800ft runway. What is the minimum constant acceleration needed?” I know I need the equation for either velocity or her position and then differentiate from there, but I’m having trouble getting started. Thanks!

1 Answer
Feb 26, 2018

#a = 29527.56# km/#hr^2#

Explanation:

Variables:
#v_i = 0# km/hr
#v_f= 120# km/hr
#d = 800# ft # = 0.24384# km
#a = ?# km/#hr^2#

Acceleration can be found from kinematic equation:
#v_f^2 = v_i^2 + 2ad#
#a = (v_f^2-v_i^2)/(2d)#

Solving:
#a = ((120)^2-(0)^2)/(2(0.24384))#
#a = 29527.56# km/#hr^2#