Question #7d602

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Answer 1 · 2017-10-20T01:05:16

185.0 m

#u = (84 km)/h = (84 × 10^3 m) / (36 × 10^2 s) = 23.3 ms^-1#

#v = (104 km)/h = (104 × 10^3 m) / (36 × 10^2 s) = 28.9 ms^-1#

#S = (v^2 - u^2) / (2a) = [(28.9 ms^-1)^2 - (23.3 ms^-1)^2] / (2 × 0.79 ms^-2) = 185.0 m#

Answer 2 · 2017-10-20T01:15:59

183.62m

Assuming that the direction of travel is a straight line:

#v^2=u^2+2as#

Where #u# is the initial velocity, #v# is the final velocity, #s# is displacement from 0 and #a# is acceleration

Before substituting in values, convert them all to the same units.

#84"kmh"^(-1)=70/3"ms"^-1#

#104"kmh"^(-1)=260/9"ms"^-1#

Substituting these values into the equation

#(260/9)^2=(70/3)^2+2*0.79*s#
#23500/81=1.58*s#
#s=183.62#

Displacement is 183.62 metres