Answer:
applying 1st eq of motion vf=vi+at we have to find a=vf-vi/t here a=50-30/2=10 so we got a=10m/s²
C.) <span>The total mass of an object can be assumed to be focused at one point, which is called its center of "Mass"
Hope this helps!</span>
Answer:
is the drop in the water temperature.
Explanation:
Given:
- mass of ice,

- mass of water,

Assuming the initial temperature of the ice to be 0° C.
<u>Apply the conservation of energy:</u>
- Heat absorbed by the ice for melting is equal to the heat lost from water to melt ice.
<u>Now from the heat equation:</u>

......................(1)
where:
latent heat of fusion of ice 
specific heat of water 
change in temperature
Putting values in eq. (1):

is the drop in the water temperature.