Answer:
It takes 34.173 s
Step-by-step explanation:
This is a relative movement exercise.
We are going to use that :
![Speed = (distance)/(time)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wbeogvaxs9gox52s9kfcvvd683ffhlf2c0.png)
And the relative movement velocity equation :
Given a particle P, and two reference systems A and B in which we know the velocity from system B relative to A and the velocity of P relative to B :
![V_(P/A) =V_(P/B) +V_(B/A)](https://img.qammunity.org/2020/formulas/physics/college/30e5fzn3kmlw303zzssnlydrqy3t37dzib.png)
Don't forget that this is a vectorial equation.In our exercise the person velocity and the speed ramp velocity have the same direction so we turn the vectorial equation into a scalar equation.
We can cover 118 m in 76 s ⇒
![Speed=(distance)/(time) \\Speed=(118m)/(76s) \\Speed=1.553(m)/(s)](https://img.qammunity.org/2020/formulas/physics/college/81qf7yg60vtazw0h1rdx8c358qouva4ft0.png)
This will be our speed relative to the speed ramp
![S_(person/ramp) =1.553(m)/(s)](https://img.qammunity.org/2020/formulas/physics/college/qmf20pohboqbdqezy7f7clq5t2oc40629q.png)
![Speed_(ramp/ground) =1.9(m)/(s)](https://img.qammunity.org/2020/formulas/physics/college/37cem23mz968xn2t7aad9bqipygyqhe97x.png)
We use the equation (in terms of speed) :
![Speed_(person/ground) =Speed_(person/ramp) +Speed_(ramp/ground)=\\ Speed_(person/ground)=1.553(m)/(s) +1.9(m)/(s) \\ Speed_(person/ground)=3.453(m)/(s)](https://img.qammunity.org/2020/formulas/physics/college/ahybm3ct6294v4w0tcczpun3u4ohwr4hu6.png)
Then →
![Speed_(person/ground) =(distance)/(time) \\3.453(m)/(s) =(118m)/(time) \\time=(118m)/(3.453(m)/(s) ) \\time=34.173s](https://img.qammunity.org/2020/formulas/physics/college/oefo7anufe1ncc3jt6ve3slxpwwaim1nrs.png)