Solving Quadratic Word Problems: Finding the Dimensions of a Rectangle

  • Thread starter Thread starter leekiss
  • Start date Start date
  • Tags Tags
    Quadratic
AI Thread Summary
The problem involves a rectangle with an area of 60 square millimeters, where increasing both dimensions by 5 millimeters results in an area of 180 square millimeters. The original dimensions are determined to be 4mm for the width and 15mm for the length. By letting the length be x mm and the width be y mm, the equation (x + 5)(y + 5) = 180 is derived. Expanding this equation leads to the relationship xy + 5x + 5y + 25 = 180, allowing for substitution of the known area. The solution process confirms the dimensions of the rectangle as 4mm and 15mm.
leekiss
Messages
1
Reaction score
0
A rectangle has an area of 60 square millimetres. If the length and width were each increased by 5 millimetres, the area would be 180 square millimetres. Find the dimensions of the original rectangle.

Could someone please help me! I have tried everything.

The answers are 4mm and 15mm.
 
Physics news on Phys.org
Let the length be x mm, and the width be y mm. What can you say about x and y? What can you say about x+5 and y+5?
 
(x + 5) x (y + 5) = 180

Expanding,
xy + 5x + 5y + 25 = 180

The value of xy is given in the question. Plug in into the equation above. The rest should be easy.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Mutual Inductance: Rectangle w/ Variable Height
Replies
2
Views
1K
Uniform Motion in 2D - A man chasing a bus
Replies
20
Views
1K
Torque On a Clock Hanging from a Nail
Replies
4
Views
3K
I The Basic Area Problem (introduction to the topic of integrals)
Replies
24
Views
3K
Finding Time and Vf: Car chase problem
Replies
3
Views
2K
Thermal Expansion: Glass rectangle
Replies
4
Views
2K
Measurements Calculation Problem
Replies
3
Views
848
MHB How do we find the dimensions of a rectangle given its perimeter and diagonal?
Replies
4
Views
2K
How 'x' (multiplication) found its way into formula of area of rectangle?
Replies
6
Views
2K
Gravitational equipotential multiple choice problem
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top