A 975-kg sports car (including driver) crosses the rounded top of a hill at determine (a) the normal force exerted by the road on the car, (b) the normal force exerted by the car on the 62.0-kg driver, and (c) the car speed at which the normal force on the driver equals zero

Respuesta :

There are missing data in the text of the problem (found them on internet):
- speed of the car at the top of the hill: [tex]v=15 m/s[/tex]
- radius of the hill: [tex]r=100 m[/tex]

Solution:

(a) The car is moving by circular motion. There are two forces acting on the car: the weight of the car [tex]W=mg[/tex] (downwards) and the normal force N exerted by the road (upwards). The resultant of these two forces is equal to the centripetal force, [tex]m \frac{v^2}{r} [/tex], so we can write:
[tex]mg-N=m \frac{v^2}{r} [/tex] (1)
By rearranging the equation and substituting the numbers, we find N:
[tex]N=mg-m \frac{v^2}{r}=(975 kg)(9.81 m/s^2)-(975 kg) \frac{(15 m/s)^2}{100 m}=7371 N [/tex]

(b) The problem is exactly identical to step (a), but this time we have to use the mass of the driver instead of the mass of the car. Therefore, we find:
[tex]N=mg-m \frac{v^2}{r}=(62 kg)(9.81 m/s^2)-(62 kg) \frac{(15 m/s)^2}{100 m}=469 N [/tex]

(c) To find the car speed at which the normal force is zero, we can just require N=0 in eq.(1). and the equation becomes:
[tex]mg=m \frac{v^2}{r} [/tex]
from which we find
[tex]v= \sqrt{gr}= \sqrt{(9.81 m/s^2)(100 m)}=31.3 m/s [/tex]

a) N = 7371 N

b) N' = 469 N

c) v = 31.32 m/sec

Given :

Mass of car = 975 Kg

Mass of driver = 62 Kg

Speed of car = 15 m/sec

Radius of hill = 100 m

Solution :

a) The car is moving in circular motion. Therefore there ia centripetal force acting on the car,

[tex]\rm mg -N=\dfrac{mv^2}{r}[/tex]

[tex]\rm N= mg -\dfrac{mv^2}{r}[/tex]  ------ (1)

Where, N is normal force exerted by the road acting on the car.

Now put the values of m, g, v and r in equation (1) we get,

[tex]\rm N = (975 \times 9.81) - (\dfrac{975\times 15^2}{100})[/tex]

[tex]\rm N = 7371\; N[/tex]

b) Centripetal force is also acting on the driver, therefore

[tex]\rm N'= m_dg -\dfrac{m_dv^2}{r}[/tex] --- (2)

where [tex]\rm m_d[/tex] is the mass of driver.

Now put the values of  [tex]\rm m_d,\;g , \; v \;and \;r[/tex] in equation (2) we get,

[tex]\rm N' = (62\times 9.81) - (\dfrac{62\times 15^2}{100})[/tex]

[tex]\rm N' = 469 \; N[/tex]

c) The car speed at which the normal force on the driver equals zero (N =0).This implies that,

[tex]\rm m_d g = \dfrac{m_dv^2}{r}[/tex]  --- (3)

Now put the values of [tex]\rm m_d,\;g\;and \;r[/tex] in equation (3) we get,

[tex]\rm 62\times 9.81 = \dfrac{62\times v^2}{100}[/tex]

[tex]\rm v = \sqrt{\dfrac{100\times 62\times 9.81}{62}}[/tex]

v = 31.32 m/sec

For more information, refer the link given below

https://brainly.com/question/13639113?referrer=searchResults