Answer:
(a) The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b)  it’s possible for a diver to enter the water with the velocity of 25 m/s if he has initial velocity of 14.4 m/s. The upward initial velocity can’t be physically attained
Explanation:
(a)
To find the final velocity [tex]V_{f}[/tex] for an object traveling distance h taking the initial vertical component of velocity as [tex]V_{i}[/tex] the kinematics equation is written as
[tex]V_{f}^{2}=V_{i}^{2}+2ah[/tex] where a is acceleration
Substituting g for a where g is gravitational force value taken as 9.81
[tex]V_{f}^{2}=V_{i}^{2}+2gh[/tex]
Since the initial velocity is zero, we can solve for final velocity by substituting figures, note that 70 ft is 21.3 m for h
[tex]V_{f}=\sqrt {(2gh)}= V_{f}=\sqrt {(2*9.81*21.3)}[/tex]= 20.44275
Therefore, the divers enter with a speed of 20.4 m/s
The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b)
The divers can enter water with a velocity of 25 m/s only if they have some initial velocity. Using the kinematic equation
[tex]V_{f}^{2}=V_{i}^{2}+2gh[/tex]
Since we have final velocity of 25 m/s
[tex]V_{i}^{2}=2gh-V_{f}^{2}[/tex]
[tex]V_{i}=\sqrt{(V_{f}^{2}-2gh)}[/tex]
[tex]V_{i}=\sqrt{(25^{2}-2*9.81*21.3)}[/tex]= 14.390761 m/s
Therefore, it’s possible for a diver to enter the water with the velocity of 25 m/5 if he has initial velocity of 14.4 m/s
In conclusion, the upward initial velocity can’t be physically attained
a) The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b)  it’s possible for a diver to enter the water with the velocity of 25 m/s if he has initial velocity of 14.4 m/s. The upward initial velocity can’t be physically attained
The velocity of an object is the rate of change of its position with respect to a frame of reference
To find the final velocity  for an object traveling distance h taking the initial vertical component of velocity as  the kinematics equation is written as
[tex]V_f^2=V_i^2+2ah[/tex]
where a is acceleration
Substituting g for a where g is gravitational force value taken as 9.81
[tex]V_f^2=V_i^2+2ah[/tex]
Since the initial velocity is zero, we can solve for final velocity by substituting figures, note that 70 ft is 21.3 m for h
[tex]V_f=\sqrt{2gh}=V_f=\sqrt{2\times 9.81\times 21.3}=20.44[/tex]
Therefore, the divers enter with a speed of 20.4 m/s
The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b)
The divers can enter water with a velocity of 25 m/s only if they have some initial velocity. Using the kinematic equation
[tex]V_f^2=V_i^2+2ah[/tex]
Since we have final velocity of 25 m/s
[tex]V_i^2=2gh-V_f^2[/tex]
[tex]V_i=\sqrt{(V_f^2-2gh)}[/tex]
[tex]V_i=\sqrt{(25^2-2\times 9.81\times 21.3)}[/tex]
= 14.390761 m/s
Therefore, it’s possible for a diver to enter the water with the velocity of 25 m/5 if he has initial velocity of 14.4 m/s
In conclusion, the upward initial velocity can’t be physically attained
To know more about Velocity follow
https://brainly.com/question/25749514
