Question

How much farther will a car traveling at 100 km/s skid than the same car traveling at 50 km/s?

A) Four times as far
B) The same distance
C) Half as far
D) Five times as far
E) Twice as far

Answer 1

option A

Step-by-step explanation:

given,

speed of car 1 = 100 Km/s

speed of car 2 = 50 Km/s

final speed = 0 Km/s

now,

skid mark when the car is moving at 100 Km/s

using equation of motion

v² = u² + 2 a s₁

0² = 100² - 2 a s₁

100² = 2 a s₁

`s_1 = (100^2)/(2a)`..........(1)

now,

skid mark when the car is moving at 50 Km/s

using equation of motion

v² = u² + 2 a s₂

0² = 50² - 2 a s₂

50² = 2 a s₂

`s_2 = (50^2)/(2a)`..........(2)

dividing equation (1)/ (2)

`(s_1)/(s_2) = (100^2)/(50^2)`

`(s_1)/(s_2) =4`

s₁ = 4 s₂

Hence, the skid mark for 100 Km/s is four time as far as 50 Km/s

The correct answer is option A