A physical change in something doesn't change what the it is. For example, if you break glass, it will still be glass. In a chemical change where there is a chemical reaction, a new thing is formed and energy is either given off or absorbed. For example, when you burn a log. The carbon in the log is reacting to the oxygen to create ashe and smoke
Part a
Answer: 17.58 km/h
Total Distance =10 km
Total time =0.5689 h
Part b
Answer: 17.626 km/h
Total Distance =42.195 km
Total time =2.3939 h
Answer:
v₂ = 7.6 x 10⁴ m/s
Explanation:
given,
speed of comet(v₁) = 1.6 x 10⁴ m/s
distance (d₁)= 2.7 x 10¹¹ m
to find the speed when he is at distance of(d₂) 4.8 × 10¹⁰ m
v₂ = ?
speed of planet can be determine using conservation of energy
K.E₁ + P.E₁ = K.E₂ + P.E₂
v₂ = 7.6 x 10⁴ m/s