Answer:
The helicopter was 1103.63 meters high when the package was dropped.
Explanation:
We consider positive speed as a downward movement
y: height (m)
t: time (s)
v₀: initial speed (m/s)
Δy = v₀t +  gt²
gt²
Δy= 15 ×15 s +
×15 s +  ×9.81
×9.81 ×(15 s)²
×(15 s)²
Δy= 1103.63 m
 
        
             
        
        
        
Answer:
a) Acceleration of the car is given as

b) Acceleration of the truck is given as

Explanation:
As we know that there is no external force in the direction of motion of truck and car
So here we can say that the momentum of the system before and after collision must be conserved
So here we will have

now we have


a) For acceleration of car we know that it is rate of change in velocity of car
so we have



b) For acceleration of truck we will find the rate of change in velocity of the truck
so we have



 
        
             
        
        
        
Answer:
I would say the net force acting on the car is in the opposite direction of the car's motion  is correct
 
        
                    
             
        
        
        
D)sound waves  the electromagnetic spectrum has to do with colors<span />
        
                    
             
        
        
        
Answer:
2.72×10^-7
Explanation:
velocity = frequency × wavelength 
2.05×10^8=7.55×10^14 wavelength 
wavelength = 2.05×10^8/7.55×10^14
wavelength = 2.72×10^-7