A typical grinding wheel is 9 in. in diameter, 1 in. thick, and weighs 6 lb. the wheel contains sic (density of 3.2 g/cm3) bonded by silica glass (density of 2.5 g/cm3); 5 vol% of the wheel is porous. the sic is in the form of 0.04 cm cubes. calculate (a) the volume fraction of sic particles in the wheel and (b) the number of sic particles lost from the wheel after it is worn to a diameter of 8 in.

ι вєℓιєνє ιт ιѕ тнє fιяѕт ¢нσι¢є(α.)

нє ѕнσυℓ∂ ѕмιℓє ρσℓιтℓу αи∂ ѕρєαк тσ тнє ρєяѕσи ωнσ ιѕ ιитєяяυριиg αfтєя тнє ∂ιѕ¢υѕѕισи

нσρє ι ¢συℓ∂ нєℓρ.

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.