Answer:
245.45km in a direction 21.45° west of north from city A
Explanation:
Let's place the origin of a coordinate system at city A.
The final position of the airplane is given by:
rf = ra + rb + rc where ra, rb and rc are the vectors of the relative displacements the airplane has made. If we separate this equation into its x and y coordinates:
rfX = raX+ rbX + rcX = 175*cos(30)-150*sin(20)-190 = -89.75km
rfY = raY + rbY + rcT = 175*sin(30)+150*cos(20) = 228.45km
The module of this position is:

And the angle measure from the y-axis is:

So the answer is 245.45km in a direction 21.45° west of north from city A
Answer:
Explanation:
Given
Weight of roller coaster is 
mass of roller coaster 
Distance traveled by roller coaster 
drag force 
velocity at top 
Suppose E is the initial energy
Conserving Energy at bottom and top



Answer:
Explanation:
Given that,
The volume of the balloon is
V = 440 × 10³ m³
Buoyant force F?
Given the density of the surrounding to be 2.58 kg/m³
ρ = 2.58 kg/m³
The buoyant force is the weight of water displaced and it is calculated using
F_b = ρVg
Where
F_b is buoyant force
ρ is density
V is the volume of the liquid displace.
g is the acceleration due to gravity
Then,
F_b = ρVg
F_b = 2.58 × 440 × 10³ × 9.81
F_b = 1.1 × 10^7 N
The answer is most likely A