Answer:
<em>The velocity of the ball as it hit the ground = 19.799 m/s</em>
Explanation:
Velocity: Velocity of a body can be defined as the rate of change of displacement of the body. The S.I unit of velocity is m/s. velocity is expressed in one of newtons equation of motion, and is given below.
v² = u² + 2gs.......................... Equation 1
Where v = the final velocity of the ball, g = acceleration due to gravity, s = the height of the ball
<em>Given: s = 20 m, u = 0 m/s</em>
<em>Constant: g = 9.8 m/s²</em>
<em>Substituting these values into equation 1,</em>
<em>v² = 0 + 2×9.8×20</em>
<em>v² = 392</em>
<em>v = √392</em>
<em>v = 19.799 m/s.</em>
<em>Therefore the velocity of the ball as it hit the ground = 19.799 m/s</em>
Answer:
Diverging lens
Explanation:
Given parameters:
Power of lens = -2.0D
Unknown:
Focal length = ?
Solution:
The power of lens is the reciprocal of the focal length;
P = 
where f is the focal length
f = 
=
The lens is a diverging lens
The average acceleration between t = 5.6 s and t = 8.5 s is 2.31 m/s²
<h3>What is acceleration?</h3>
Acceleration is defined as the rate change of velocity with time.
acceleration a = (Δv) / (Δt)
An object is moving with initial velocity u =5.7 m/s and its final velocity v= -1.0 m/s.
Time taken for the change in speed, t= 8.5 - 5.6 = 2.9 seconds
The acceleration is given by
a = (-1 - 5.7)/ 2.9
a = - 2.31 m/s²
|a | = 2.31 m/s²
Thus, the object's acceleration is 2.31 m/s²
Learn more about acceleration.
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