Answer:
Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous. The process of a solid becoming a liquid is called melting.
Answer:
a) u = 30.29 m/s
b) t = 2.09 s
Explanation:
given,
velocity = 45 m/s
angle (θ) = 50°
horizontal velocity = 45 cos 50°
time taken to reach 150 m.
times = 
t = 5.19 s
a) height of arrow



s = 46.78 m
v² - u² = 2 g s
u² = 2 × 9.81 × 46.78
u = 30.29 m/s
b) time taken by the apple = 
= 3.09 s
time after which it has to be thrown = 5.19-3.09 = 2.1 s
Air pressure decreases as altitude increases. this is because air pressure is caused by the gravity of earth, the gravity pulls on the air, compacting it and making a pressure.
But as we go higher, gravity decreases, causing less pull on the air resulting in less air pressure.<span />
the answer is D cuz electricity is a conductive