Answer:
hence option A is correct
Explanation:
heat required from -9°C to 0°C ice = mass × specific heat of ice ×change in temperature
heat required from -9°C to 0°C ice = 7×2100×9 =132300 J =0.1323 MJ
( HERE SPECIFIC HEAT OF ICE IS A CONSTANT VALUE OF 2100
J/(kg °C )
heat required from 0°C ice to 0°C water = mass× specific heat of fusion of ice
= 7×3.36×10^5
= 2.352 × 10^6 J
= 2.352 MJ
TOTAL HEAT ENERGY REQUIRED = 0.1323 MJ +2.352 MJ
= 2.4843 MJ
hence option A is correct
Hysical science is defined as the study of observable phenomena in the universe.
<span>the main idea of physical science is known as the "scientific method". </span>
<span>this method states: </span>
<span>observe a "real" ( not imaginary ) phenomena. </span>
<span>make a hypothesis ( or theory / idea ) that EXPLAINS this phenomena. </span>
<span>conduct a real experiment to test this hyothesis. </span>
<span>confirm that the experiment validates the original hypothesis and if necessary amend the theory. </span>
<span>it has worked so well that the very communication you are having with me is a result of the wonders of physical science. </span>
During the phase transition vapour --> liquid water, the temperature of the water does not change; the molecules of water release heat and the amounf of heat released is equal to

where
m is the mass of the water

is the latent heat of evaporation.
For water, the latent heat of evaporation is

, while the mass of the water is

so, the amount of heat released in the process is
Answer:
0.19m/s²
Explanation:
Initial velocity(u) = 50×1000/60×60
=13.88 m/s
Final velocity(v) = 36.5×1000/60×60
=10.13 m/s
Acceleration(a) = v-u/t
=10.13-13.88/19.5
a= -0.19m/s²
-a = 0.19m/s²
The magnitude of retar dation is 0.19m/s²
Answer:
15.5 m/s.
Explanation:
Potential energy of the balloon has been converted to kinetic energy.
potential energy = kinetic energy.
mgh = ½mv².
10* 10* 12= ½ *10 *v²
1200 = 5v²
v²=1200÷5
v=√240
v= 15.49~15.5 m/s.