Smiple but I'm stuck

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caveman721

Full Member
7+ Year Member
There are two questions

1)A motorcycle starts from rest and has a constant acceleration. In a certain time interval, its displacement triples. In the same time interval, by what factor does its velocity increase?

The answer is 1.73 how do they get that as well what is the math process.

2)A power boat, starting from rest, maintains a constant acceleration. After a certain time "t", its displacement and velocity are "r" and "V". At time "2", what would be its dispalcement and velocity, assuming the acceleration remains the same?

Again help with the reasoning as well as the process to come to the answer.

Thank you

Pisiform

Oh Crap!!!
10+ Year Member
1)

v^2 = u^2 + 2as
v^2 = 0 + 2(a)(3) (acc is constant and everything else is constant)
v = sqrt 3 = 1.73

For question 2

x=vit+1/2at^2
x=0+(Vf/2t)t^2
plug in for t
x=vf
vf^2=vi^2+2ax
a=Vf/t
x=Vf
plug in for t
and vf=1
and x=1
velocity =1m/s
displacement 1 m