The specific heat of wood is about 1,700 j/kg. °c. how much energy is required to heat a 12 kg piece of wood from 20 degrees * c to 30 degrees * c ?

204 kJ

Explanation:

Heat energy can be calculated using

Q=mcθ

where Q = Heat energy

           m =mass

           c = specific heat capacity

           θ =temperature difference

Q = 12 * 1700*10

   = 204000 J

   = 204 kJ

sonar - device which is used to find the submit submarines, sankalp ship. sonar waves consists of a transmitter and detector which are installed in the observation centre on board of a ship. the ultrasonic waves are sent into the sea at high frequency about 1000 khz in all direction.

  distance on the y-axis and time on the x-axis.

explanation:

the instantaneous velocity = change in position/time taken

the slope of the graph should give instantaneous velocity.

  slope of a graph = change in value of y -axis / change in values of x -axis

  comparing both the equations

    change in value of y -axis = change in position

  change in values of x -axis = time taken

so position values should be on the y axis and time values should be on the x axis.

distance on the y-axis and time on the x-axis.