Answer:
90°
Explanation:
The angle will be 90° when momentum for a system can be conserved in one direction while not being conserved in another.
The example can be
If we apply force on an object horizontally in west direction, then as in other direction south or north we cannot apply the principal of momentum conservation.
Answer:
The specific heat capacity of the zinc metal measured in this experiment is 0.427 J/g.°C
Explanation:
From the experimental data, the water loses heat because its initial temperature is greater than the final temperature of the mixture. On the other hand, the zinc metal gains heat because its initial temperature is less than the final temperature of the mixture
Heat loss by water = Heat gain by zinc metal
m1C1(T1 - T3) = m2C2(T3 - T2)
m1 is mass of water = 55.4 g
C1 is specific heat capacity of water = 4.2 J/g.°C
m2 is mass of zinc metal = 23.4 g
C2 is specific heat capacity of zinc metal
T1 is the initial temperature of water = 99.61 °C
T2 is the initial temperature of zinc metal = 21.6 °C
T3 is the final temperature of the mixture = 96.4 °C
55.4×4.2(99.61 - 96.4) = 23.4×C2(96.4 - 21.6)
746.9028 = 1750.32C2
C2 = 746.9028/1750.32 = 0.427 J/g.°C
The correct answer is:
D. Electromagnetic waves.
The arrows represent electromagnetic waves.

The term used to describe the quantity of matter that a body possesses is mass.
The percentage of energy available to each organism is always 10 percent .