Question

Guys I need help

Answer 1

Answer:

Activity 1:-

1) Pi (π) is the ratio of circumference and the diameter of the circle which is 22/7. So

$\frac{c}{d} =\pi = \frac{22}{7}$

$=> c = \frac{22}{7} d$ where circumference is directly proportional to diameter (d).

2) Area of a parallelogram = Altitude × Base

Base = 10 cm. So ,

$A = 10a$ where area (A) is directly proportional to altitude (a).

3) Let the fare of 1 unit distance be f

So, for distance d , total fare (F) will be $F = fd$ where total fare (F) is directly proportional to distance (d).

4) Let the distance be 'D' , speed be 's' & time be 't' .

We know that $s = \frac{D}{t}$ where speed (s) is directly proportional to distance (D) & inversely proportional to time (t).

5) We know that area of a square (A) = side² (s²)

$=> A = s^{2}$ where area(A) is directly proportional to side(s).

Activity 2:-

1) p is directly proportional to sum of u & w.

⇒ p ∝ u + w

⇒ p = k (u + w)

Putting the values of p , u & w

⇒ 14 = k(4 + 3)

⇒ 7k = 14

⇒ k = 14/7 = 2

2) r is directly proportional to square of t.

⇒ r ∝ t²

⇒ r = k × t²

Putting the values of r & t

⇒ 16 = k × 16²

⇒ k = 16² ÷ 16 = 16

3) y is directly proportional to cube root of x.

⇒ y ∝ ∛x

⇒ y = k × ∛x

Putting the values of x & y ,

⇒ 2 = k × ∛27

⇒ 3k = 2

⇒ k = 2/3

4) z is directly proportional to cube of d.

⇒ z ∝ d³

⇒ z = k × d³

Putting the values of d & z ,

⇒ 5 = k × 2³

⇒ 8k = 5

⇒ k = 5/8

5) Total Surface Area (SA) is directly proportional to square of the sides (s).

⇒ SA ∝ s²

⇒ SA = k × s²

Putting the values of SA & s ,

⇒ 96 = k × 4²

⇒ 16k = 96

⇒ k = 96/16 = 6