Loading...
Overspeeding increases fuel consumption and decreases fuel economy as a result of tyre rolling friction and air resistance. While vehicles reach optimal fuel economy at different speeds, fuel mileage usually decreases rapidly at speeds above 80 km/h. The relation between fuel consumption F (l/100 km) and speed V (km/h) under some constraints is given as F = V²/500 – V/4 + 14. On the basis of the above information, answer the following questions :
If the sides of a square are decreasing at the rate of 1·5 cm/s, the rate of decrease of its perimeter is :
The volume of a cube is increasing at the rate of 6 cm³/s. How fast is the surface area of cube increasing, when the length of an edge is 8 cm?
Given a curve y = 7x − x³ and x increases at the rate of 2 units per second. The rate at which the slope of the curve is changing, when x = 5 is :
The area of the circle is increasing at a uniform rate of 2 cm²/sec. How fast is the circumference of the circle increasing when the radius r = 5 cm ?
A rectangular visiting card is to contain 24 sq.cm. of printed matter. The margins at the top and bottom of the card are to be 1 cm and the margins on the left and right are to be 1½ cm as shown below :
© 2026 PadhAiPro. This question is provided for educational purposes.