Explanation:
a) d = ½.a.t²
200 = ½(4)t²
200 = 2t²
t² = 200/2
t² = 100
t =√100 = 10 s
b) Vt = a. t
= 4(10)
= 40 m/s
c) V av. = d/t = 200/10 = 20m/s
Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2.
Hot air rises<span> because when you </span>heat air<span> (or any other gas for that matter), it expands. When the </span>air<span> expands, it becomes less dense than the </span>air<span>around it. The less dense </span>hot air<span> then floats in the more dense cold </span>air<span> much like wood floats on water because wood is less dense than water.</span>
Answer:
a) false b) true c) true d) false and e) true
Explanation:
a) false. All the energy applied is used for the phase change, so the temperature remains constant.
b) true. The kinetic energy is associated with the speed of the particles and they have more mobility in the liquid, therefore, more kinetic energy.
c) true. Since energy is used for state change
d) false. In general, mobility and temperature are proportional
e) true. Heat is the source of energy for the change of state
