A 1200.0-kg car is traveling at 19m/s. The driver suddenly slams on the brakes and skids to a stop. The coefficient of kinetic f

Question

3 years ago

14

riction between the tires and the road is 0.80. For what length of time is the car skidding?
1.7 s

2.9 s

3.9 s

2.4 s

1 answer:

Alja [10] · Answer 1 · 2022-08-05T20:25:47+03:00

<h2>Answer</h2>

option D)

2.4 seconds

<h2>Explanation</h2>

Given in the question,

mass of car = 1200kg

speed of car = 19m/s

Force due to direction of travel

F = ma

= 12000(a)

Force to due frictional force in reverse direction

-F = mg(friction coefficient)

= -12000(9.81)(0.8)

<h2>-mg(friction coefficient) = ma </h2>

(cancelling mass from both side of equation)

g(0.8) = a

(9.81)(0.8) = a

a = 7.848 m/s²

<h2>Use Newton Law of motion</h2><h3>vf - vo = a • t</h3>

where vf = final velocity

vo = initial velocity

a = acceleration

t = time

0 - 19 = 7.8(t)

t = 19/7.8

= 2.436 s

≈ 2.4s