A train starts from rest and accelerates uniformly until it has traveled 2.1 km and acquired a forward velocity of $24 \mathrm {~m} / \mathrm { s }$ The train then moves at a constant velocity of $24 \mathrm {~m} / \mathrm { s }$ for 400 s. The train then slows down uniformly at $0.065 \mathrm {~m} / \mathrm { s } ^ { 2 }$ until it is brought to a halt. The distance traveled by the train while slowing down is closest to
A)4.4 km.
B)4.2 km.
C)4.0 km.
D)3.8 km.
E)3.6 km.

Question

Quizplus · Accepted Answer

The distance traveled while slowing down can be calculated using the formula $ v^2 = u^2 + 2as $, where $ v = 0 $, $ u = 24 \, \text{m/s} $, and $ a = -0.065 \, \text{m/s}^2 $. Solving for $ s $ gives approximately 4.4 km.

A Train Starts from Rest and Accelerates Uniformly Until It 24 m/s24 \mathrm {~m} / \mathrm { s }24 m/s

A Train Starts from Rest and Accelerates Uniformly Until It $24 \mathrm {~m} / \mathrm { s }$