Question 113: Motion in 1D

Question

A car is moving with speed of $$150 \mathrm{~km} / \mathrm{h}$$ and after applying the break it will move $$27 \mathrm{~m}$$ before it stops. If the same car is moving with a speed of one third the reported speed then it will stop after travelling ___________ m distance.

Accepted Answer

$${F_R}\,d = {1 \over 2}m{v^2}$$
$${{{d_2}} \over {{d_1}}} = {\left( {{{{v_2}} \over {{v_1}}}} ight)^2} = {\left( {{1 \over 3}} ight)^2}$$
$${d_2} = {d_1} 	imes {1 \over 9} = 3m$$

Motion in 1D

A car is moving with speed of $150 \mathrm{~km} / \mathrm{h} and after applying the break it will move 27 \mathrm{~m}$ before it stops. If the same car is moving with a speed of one third the reported speed then it will stop after travelling ___________ m distance.

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