4.76 A car starts from rest on a curve of radius 120 m and accelerates tangentially at 1.0 m/s2 . Through what angle will the car have traveled when the magnitude of its total acceleration is 2.0 m/s2

Respuesta :

Answer:

The angle is 28.64°

Explanation:

Given:

Radius of curve [tex]r = 120[/tex] m

Tangential acceleration [tex]a_{t} = 1[/tex] [tex]\frac{m}{s^{2} }[/tex]

Total acceleration [tex]a = 2[/tex] [tex]\frac{m}{s^{2} }[/tex]

From equation total acceleration,

   [tex]a = \sqrt{a_{t}^{2}+ a_{c}^{2} }[/tex]

Find centripetal acceleration,

  [tex]a_{c} = \sqrt{a^{2}- a_{t} ^{2} }[/tex]

  [tex]a_{c} = \sqrt{4-1 }[/tex]

  [tex]a_{c} = 1.73[/tex] [tex]\frac{m}{s^{2} }[/tex]

From equation of centripetal acceleration,

  [tex]a_{c} = \frac{v^{2} }{r}[/tex]

   [tex]v = \sqrt{a_{c} r }[/tex]

   [tex]v = \sqrt{207.6}[/tex]

   [tex]v = 14.41[/tex] [tex]\frac{m}{s}[/tex]

From the equation of kinematics,

   [tex]d = \frac{v^{2} }{2a_{t} }[/tex]

   [tex]d = \frac{207.6}{2 \times 1.73}[/tex]

   [tex]d = 60[/tex] m

For finding the angle,

   [tex]d = r\theta[/tex]

   [tex]\theta = \frac{d}{r}[/tex]

   [tex]\theta = \frac{60}{120}[/tex]

   [tex]\theta = 0.5[/tex]  rad

   [tex]\theta =[/tex] 28.64°

Therefore, the angle is 28.64°