Answer:
Impulse = change in momentum w bounce
There are 2 impulses acting. Recoil of the fan going the negative direction and the impulse of the air bouncing off the sail. The greater impulse will bounce so the direction will be to the right moving the craft.
 
        
             
        
        
        
Wow !  This is not simple.  At first, it looks like there's not enough information, because we don't know the mass of the cars.  But I"m pretty sure it turns out that we don't need to know it.
At the top of the first hill, the car's potential energy is
                                  PE = (mass) x (gravity) x (height) .
At the bottom, the car's kinetic energy is
                                 KE = (1/2) (mass) (speed²) .
You said that the car's speed is 70 m/s at the bottom of the hill, 
and you also said that 10% of the energy will be lost on the way 
down.  So now, here comes the big jump.  Put a comment under 
my answer if you don't see where I got this equation:
                                   KE = 0.9  PE
        (1/2) (mass) (70 m/s)² = (0.9) (mass) (gravity) (height)      
Divide each side by (mass):  
               (0.5) (4900 m²/s²) = (0.9) (9.8 m/s²) (height)
(There goes the mass.  As long as the whole thing is 90% efficient,
the solution will be the same for any number of cars, loaded with
any number of passengers.) 
Divide each side by (0.9):
               (0.5/0.9) (4900 m²/s²) = (9.8 m/s²) (height)
Divide each side by (9.8 m/s²):
               Height = (5/9)(4900 m²/s²) / (9.8 m/s²)
                          =  (5 x 4900 m²/s²) / (9 x 9.8 m/s²)
                          =  (24,500 / 88.2)  (m²/s²) / (m/s²)
                          =        277-7/9    meters
                                  (about 911 feet)
        
             
        
        
        
Answer:
The answer is below
Explanation:
a) The initial velocity (u) = 24 m/s
We can solve this problem using the formula:
v² = u² - 2gh
where v = final velocity, g= acceleration due to gravity = 9.8 m/s², h = height.
At maximum height, the final velocity = 0 m/s
v² = u² - 2gh
0² = 24² - 2(9.8)h
2(9.8)h = 24²
2(9.8)h = 576
19.6h = 576
h = 29.4 m
b) The time taken to reach the maximum height is given as:
v = u - gt
0 = 24 - 9.8t
9.8t = 24
t = 2.45 s
The total time needed for the apple to return to its original position = 2t = 2 * 2.45 = 4.9 s
 
        
             
        
        
        
Answer:
C
Explanation:
they involve breaking and making chemical bonds
 
        
             
        
        
        
8.64
×10^4
this is 86400 in scientific notation