Question

part a
the total mass of the runner is 56 kg. based on this information, what is the acceleration and direction of the runner?
1.42 m/s² backward
1.00 m/s² forward
1.00 m/s² backward
1.42 m/s² forward
part b

Explanation:

Step1: Calculate net force

Net force \(F_{net}=F_{applied}-F_{air}\). Given \(F_{applied} = 68N\) and \(F_{air}=12N\), so \(F_{net}=68 - 12=56N\) (forward, since \(F_{applied}>F_{air}\)).

Step2: Use Newton's second law \(F = ma\)

We know \(F_{net}=56N\) and \(m = 56kg\). Rearranging \(a=\frac{F_{net}}{m}\), substituting values \(a=\frac{56}{56}=1m/s^{2}\).

Answer:

1.00 m/s² forward