The young�s modulus for steel is 20.7*1010 n/m2. how much will a 2.5 mm diameter wire 12 cm long, be strained when it supports a load of 450 n?

ΔL = 53.14*10⁻⁶ m

Explanation:

Given

E = 20.7*10¹⁰ N/m²

D = 2.5 mm = 2.5*10⁻³ m

L = 12 cm = 0.12 m

P = 450 N

ΔL = ?

We can use the formula

ΔL = P*L / (A*E)

where    A = π*D² / 4 = π*(2.5*10⁻³ m)² / 4

⇒   A = 4.908*10⁻⁶ m²

then

ΔL = (450 N)*(0.12 m) / (4.908*10⁻⁶ m²*20.7*10¹⁰ N/m²) = 53.14*10⁻⁶ m

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it