It depends on what they are
Answer:
heat energy that is needed to raise tempeture
Answer:
0.002833 sec
Explanation:
Speed of light in vacuum is 
Given distance = 850 km = 850×1000=850000 m
We have to calculate the time that light take to travel the distance 850 km
Time 
So the time taken by light to travel 850 km is 0.002833 sec
Answer:
L=55.9m
Explanation:
The equation for the period of a simple pendulum is:

In our case what we know is the period and the acceleration of gravity, and we need to know the length of the pendulum, so we can write:

Which for our values is:

Water expands when it freezes (that's why you should never put closed, fully filled water bottles in the freezer !)