what does the specific heat of a substance describe?

note: "specific heat" is a scientific term. don't just guess the answer! it's not a simple concept.

Explanation:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

The substances with higher value of specific heat capacity require more heat to raise the temperature by one degree as compared the substances having low value of specific heat capacity.For example,

The specific heat capacity of oil is 1.57 j/g. K and for water is 4.18 j/g.K. So, water take a time to increase its temperature by one degree by absorbing more heat while oil will heat up faster by absorbing less amount of heat.

Consider that both oil and water have same mass of 5g and change in temperature is 15 K. Thus amount of heat thy absorbed to raise the temperature is,

For oil:

Q = m.c. ΔT

Q = 5 g× 1.67 j/g K × 15 K

Q = 125.25 j

For water:

Q = m.c. ΔT

Q = 5 g× 4.18 j/g K × 15 K

Q = 313.5 j

we can observe that water require more heat which is 313.5 j to increase its temperature.

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied