Question

Ch-11 Perimeter and Area • Write the no. of all the doors and windows in the house with their dimensions. • Find the area of all the doors and windows. • Find the cost of painting the doors and windows at the rate of Rs.5 per square cm. Write in full answer please 8 doors and 7 windows​

Answer 1

Answer:

Dimensions of wall:

Length = 14 m

Breadth = 10 m

Height = 6.5 m

Dimensions of windows

Length = 1.5 m

Breadth = 1 m

And,Length of doors = 2.5 m

Breadth of doors = 1.2 m

Cost = RS 35 per m

2

Now,

Area of four walls = 2(Length of walls × Height of walls) +2(Breadth of walls × Height of walls)

=2(14×6.5)+2(10×6.5)

=182+130

=312

⇒ Area of four walls is 312m

2

Area of two doors = 2(Length of doors × Breadth of doors)

=2(2.5×1.2)

=6

⇒ Area of two doors is 6m

2

Area of four windows = 4(Length of windows × Breadth of windows)

=4(1.5×1)

=6

⇒ Area of four windows is 6m

2

Therefore,

Area to be painted = Area of 4 walls − (Area of 2 doors + Area of 4 windows)

=312(6+6)

=300

⇒ Area to be painted is 300m

2

Cost of painting =300m

2

× Rs 35 per m

2

=Rs10500

Answer 2

You are being asked to deploy this equation:

force = mass X acceleration, or f = m*a

m = 1000 kg

velocity 45 km/hr = 12.5 m/s so

acceleration a = -2.5 m/s^2 Therefore

f = m*a = 1000 * -2.5 = -2500 newtons