D. When a substance reacts with another substance, it shows its chemical property
Answer:
a) 
s
b) 3.41 mm
Explanation:
a)
We take the speed of light, c = 
m/s and the refractive index of glass as 1.517.
Speed = distance/time
Time = distance/speed
Refractive index, n = speed of light in vacuum / speed of light in medium
b)
We take the refractive index of water as 1.333.
Speed in water = speed in vacuum / refractive index of water
Distance = speed * time
d = 3.41 mm
The parcel will undergo projectile motion, which means that it will have motion in both the horizontal and vertical direction.
First, we determine how long the parcel will fall using:
s = ut + 1/2 at²
where s will be the height, u is the initial vertical velocity of the parcel (0), t is the time of fall and a is the acceleration due to gravity.
5.5 = (0)(t) + 1/2 (9.81)(t)²
t = 1.06 seconds
A
Answer:
340 W
Explanation:
Power = change in energy / change in time
P = ΔKE / Δt
P = ½ mv² / Δt
P = ½ (90 kg) (15 m/s)² / (30 s)
P = 337.5 W
Rounded to 2 significant figures, the power is 340 W.
