#### Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.

Click to Chat

1800-1023-196

+91 7353221155

CART 0

• 0
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

# the cost of fuel for running a bus is proportional to the square of the speed generated in km/hr. it costs Rs.48 per hour when the bus is mooving at the speed of 20km/hr .what is the most economical speed if the fixed charges are Rs.108 for an hour,over and above the running charges.

Grade:12

## 1 Answers

Jitender Singh IIT Delhi
askIITians Faculty 158 Points
6 years ago
Ans:
Let cost of fuel be ‘P’ Rs/hr & spped of vehicle be ‘v’ in km/hr.
$P \alpha v^{2}$
$P = av^{2}, a = constant$
$48 = a(20)^{2}$
$a = \frac{48}{20^{2}} = \frac{3}{25}$
$P = \frac{3}{25}v^{2}$
There is something missing in the question. How much distance bus need to cover should mention. Otherwise, at
$P = 108 (\frac{Rs.}{hr})$
$108 = \frac{3}{25}v^{2}$
$v = 30 (\frac{km}{hr})$
Thanks & Regards
Jitender Singh
IIT Delhi
askIITians Faculty

## ASK QUESTION

Get your questions answered by the expert for free