Question
A metal plate with a circular hole at the centre is
heated. What will happen to the area of the hole?Solution
Assuming the disc is uniform and isotropic (the same in different directions), the hole will expand in the same ratio as the metal. It is because the thermal expansion equation applies to all lengths associated with the metal, including the circumference of the hole, since the edge of the hole is made out of metal. And if the circumference of the hole expands, so does the diameter.
Radius of a cylinder is increased by 20% and height reduces by 40% so what effect on the volume of cylinder?
Angle bisectors of Q and R meet at point S, inside the triangle PQR. If angle QSR = 128˚ , then the measure of angle P is:
The ratio of length to breadth of a rectangle is 5:4, respectively. Perimeter of rectangle is 162 cm. If each side of a square is 25% more than the brea...
Steel is used to make a hemispherical bowl that is 0.3 cm thick. The bowl's inner radius is 9 cm. Find the bowl's outside curved surface.
Sides of a parallelogram are in the ratio 4:3. Its area is 432 sq. units. Altitude on the greater side is 12 units. Altitude on the smaller side is:
The length and breadth of a rectangle are increased by 30% and 40% respectively. The increase in the area of the resulting rectangle will be:
- In a right-angled triangle, if the shortest median is 6.2 cm, calculate the length of the hypotenuse.
The length of a width is 21 cm and the side of a square is 25 cm less than the length and width of the rectangle. If perimeter of the rectangle is 30 cm...
A rectangular frame of size 120 cm (length) x 140 cm (breadth) is to be surrounded by stickers of 2 cm x 2 cm size. How many stickers would be require...
The perimeter of a rectangle is 230 meters, and the difference between length and breadth is 15 meters. Find the area of the rectangle.
