Answer: 16.3 seconds 
Explanation: Given that the 
Initial velocity U = 80 ft/s
Let's first calculate the maximum height reached by using third equation of motion. 
V^2 = U^2 - 2gH
Where V = final velocity and H = maximum height. 
Since the toy is moving against the gravity, g will be negative. 
At maximum height, V = 0
0 = 80^2 - 2 × 9.81 × H
6400 = 19.62H
H = 6400/19.62
H = 326.2
Let's us second equation of motion to find time.
H = Ut - 1/2gt^2
Let assume that the ball is dropped from the maximum height. Then,
U = 0. The equation will be reduced to
H = 1/2gt^2
326.2 = 1/2 × 9.81 × t^2
326.2 = 4.905t^2
t^2 = 326.2/4.905
t = sqrt( 66.5 )
t = 8.15 seconds 
The time it will take for the rocket to return to ground level will be 2t.
That is, 2 × 8.15 = 16.3 seconds 
 
        
             
        
        
        
In a free body diagram for an object projected upwards;
- the acceleration due to gravity on the object is always directed downwards.
- the velocity of the object is always in the direction of the object's motion.
An object projected upwards is subjected to influence of acceleration due to gravity.
As the object accelerates upwards, its velocity decreases until the object reaches maximum height where its velocity becomes zero and as the object descends its velocity increases, which eventually becomes maximum before the object hits the ground.
To construct a free body diagram for this motion, we consider the following;
- the acceleration due to gravity on the object is always directed downwards
- the velocity of the object is always in the direction of the object's motion.
<u>For instance:</u>
upward motion for velocity  ↑        downward motion for velocity  ↓
                                               ↑                                                            ↓
                                               ↑                                                            ↓
acceleration due to gravity ↓
                                              ↓
                                              ↓
Learn more here: brainly.com/question/13235430
 
        
             
        
        
        
Answer:
Explanation:
The cannonball goes a horizontal  distance of 275 m . It travels a vertical distance of 100 m 
Time taken to cover vertical distance =  t , 
Initial velocity u = 0 
distance s = 100 m 
acceleration a = 9.8 m /s² 
s = ut + 1/2 g t²
100 = .5 x 9.8 x t²
t = 4.51 s 
During this time it travels horizontally also uniformly so 
horizontal velocity Vx = horizontal displacement / time 
= 275 / 4.51 = 60.97 m /s 
Vertical velocity Vy 
Vy = u + gt 
= 0 + 9.8 x 4.51 
= 44.2 m /s 
Resultant velocity 
V = √ ( 44.2² + 60.97² )
= √ ( 1953.64 + 3717.34 )
= 75.3 m /s 
Angle with horizontal Ф
TanФ = Vy / Vx 
= 44.2 / 60.97 
= .725
Ф = 36⁰ . 
 
        
             
        
        
        
Answer:
Baby are born due to the fertilization of Owen or egg present in vigina due to the fertilization from sperms
 
        
                    
             
        
        
        
Using K.E=1/2MV^2
answer is 125joules