Ask
Login
0
7.0kviews
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.
written 7.8 years ago by gravatar for teamques10 teamques10 ★ 65k •   modified 4.0 years ago

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
engineering mechanics
ADD COMMENT EDIT
1 Answer
2
1.4kviews
written 7.8 years ago by gravatar for teamques10 teamques10 ★ 65k

Given: $u=90$ kmph $=25 m/s $

$$t=12 sec \space\space\space S=250 m $$

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 …

Create a free account to keep reading this post.

and 3 others joined a min ago.

ADD COMMENT EDIT
Please log in to add an answer.