On Earth, the acceleration due to gravity is (-9.8 meters per second) per second.
If the school, the roof, and the pencil are on Earth,
then after 3 seconds, the pencil's speed is
[ (-9.8 meters per second)/second ] times [ 3seconds ] = <u>-29.4 meters per second </u>
Answer:19.5 J
Explanation:
Given
mass of block=3 kg
angular frequency=20 rad/sec
spring constant 
we know total energy remain conserved


Where
=kinetic energy
=potential Energy





When mass reaches amplitude its velocity becomes zero
there is only potential energy which is equal to Total energy

Answer:

Explanation:
m = Mass of person = 70 kg
c = Specific heat of human body = 
= Change in temperature
Time taken is 1 hour
Heat is given by

The rise in temperature is 