Find the change in the thermal energy of a 20-kg wooden chair that warms from 15℃ to 20℃ if the specific heat of wood is 700 J/(kg℃) *

70000J

Explanation:

Given parameters:

Mass of wooden chair  = 20kg

Initial temperature = 15°C

Final temperature = 20°C

Specific heat of wood = 700J/kg°C

Unknown:

Thermal energy change = ?

Solution:

The wood must have significantly absorbed some certain amount of heat to cause a thermal energy change into this. This quantity of heat it takes in will cause the thermal change.

  Quantity of heat = m c Δt

       where m is the mass of the wooden chair

                    c is the specific heat of the wood

                   Δt is the change in temperature

Input the variables;

        H  =  20 x 700 x (20 - 15)

              = 70000J

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer