A motorist is travelling at 90 kmph, when he observes a traffic signal 250 m ahead of him turns red. The traffic signal is timed to stay red for 12 secs.

Welcome back.

and 3 others joined a min ago.

1.1kviews

written 7.9 years ago by

teamques10 ★ 68k

modified 2.8 years ago by

pedsangini276 • 4.8k

If the motorist wishes to pass the signal without stopping just as it turns green, Determine i) The required uniform deceleration of motor ii) The speed of motor as it passes the signal.

Mumbai University > FE > Sem 1 > Engineering Mechanics

Marks : 04

Years : DEC 2015

engineering mechanics

ADD COMMENT EDIT

1 Answer

14views

written 7.9 years ago by

teamques10 ★ 68k

• modified 7.9 years ago

Given: $u=90 kmph=25 m/s \\ t=12 sec\\ S=250 m $

Applying, $S= ut+(1/2)at2 \\ 250= 25(12) + 0.5(a)(144) \\ a= - 0.694 m/s2 $

Now, applying $v = u +at \\ v = 25+(-0.694)(12) = 16.67 m/s $

Uniform deceleration of motor is - 0.694 m/s2 & the speed of motor as it passes the signal is 16.67 m/s

ADD COMMENT EDIT

Community

Content

Company