Email
Chat with tutor
logo

Ask Questions, Get Answers

X
 
Answer
Comment
Share
Q)

The distince $x$ meters traveled by a vehical in time $t$ seconds after the brakes are applied is given by:$\;x=20 t-\large\frac{5}{3}$$t^{2}$. Determine the speed of the vehicle (in km/hr) at the instant the brakes are applied

This is part 1st of a 2 part question, split as 2 separate questions here.

1 Answer

Comment
A)
Toolbox:
  • If $s=f(t)$ is the distance function, representing the distance 's' travelled by a particle in time t, then the velocity and acceleration functions are $v=\large\frac{ds}{dt}$$=t'(t)$ and $a=\large\frac{d^2s}{dt^2}=f''(t)$
  • When a particle starts from rest,velocity v and time t are 0. When a particle is thrown up, it reaches maximum height at which $v=0$ and then falls back to earth. When a moving particle comes rest, $v=0$
$x=20t-\large\frac{5}{3}$$t^2$ when the brakes are applied
Velocity is $\large\frac{dx}{dt}$$=20- \large\frac{5}{3}$$ \times 2t$
$\qquad\qquad=20-\large\frac{10}{3}$$t$
$t=0$ When the brakes are applied.
The speed at $t=0$ is $20\;m/sec$

 

Help Clay6 to be free
Clay6 needs your help to survive. We have roughly 7 lakh students visiting us monthly. We want to keep our services free and improve with prompt help and advanced solutions by adding more teachers and infrastructure.

A small donation from you will help us reach that goal faster. Talk to your parents, teachers and school and spread the word about clay6. You can pay online or send a cheque.

Thanks for your support.
Continue
Please choose your payment mode to continue
Home Ask Homework Questions
Your payment for is successful.
Continue
Clay6 tutors use Telegram* chat app to help students with their questions and doubts.
Do you have the Telegram chat app installed?
Already installed Install now
*Telegram is a chat app like WhatsApp / Facebook Messenger / Skype.
...