A 1370-kg car is moving due east with an initial speed of 29.0 m/s. After 6.37 s the car has slowed down to 15.8 m/s. Find the magnitude of the net force that produces the deceleration.Number________ Units________

Respuesta :

We are given that a car decelerates from 29 m/s to 15.8 m/s in 6.37 seconds. To determine the force that causes de deceleration we will use Newton's second law:

[tex]F=ma[/tex]

Where:

[tex]\begin{gathered} F=\text{ force} \\ m=\text{ mass} \\ a=\text{ acceleration} \end{gathered}[/tex]

We are given the mass therefore we need to determine the acceleration. To do that we will use the following equation of motion:

[tex]v_f=v_0+at_{}[/tex]

Where:

[tex]\begin{gathered} v_f,v_0=\text{ final and initial velocities} \\ a=\text{ acceleration} \\ t=\text{ time} \end{gathered}[/tex]

Now, we solve for the acceleration. First, by subtracting the initial velocity from both sides:

[tex]v_f-v_0=at[/tex]

Now, we divide both sides by "t":

[tex]\frac{v_f-v_0}{t}=a[/tex]

Now, we plug in the given values of velocity and time:

[tex]\frac{15.5\frac{m}{s}-29\frac{m}{s}}{6.37s}=a[/tex]

Solving the operations:

[tex]-2.12\frac{m}{s^2}=a[/tex]

Now, we use this value together with the mass to determine the force:

[tex]F=(1370\operatorname{kg})(-2.12\frac{m}{s^2})[/tex]

Solving the product:

[tex]F=-2903.45N[/tex]

Therefore, the magnitude of the force is 2903.45 Newtons.

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