Respuesta :
Answer:
T= 2.35 seconds
Step-by-step explanation:
⇒The question is on the time of flight.
⇒Time of flight is the time taken for a projected object to reach the ground.It depends on the projectile angle and the initial velocity of the projectile
Given;
Initial velocity of ball= 110ft./sec.
The projectile angle= 20°
Acceleration due to gravity, g=32 ft./s²
⇒Formulae for time of fright T= (2×u×sin Ф)/g
Where T=time of fright, u=initial velocity of projectile, Ф=projectile angle and g=acceleration due o gravity.
Substituting values
T= (2×u×sin Ф)/g
T=( 2×110×sin 20°) / 32
T= 2.35 seconds
Answer:
Option B - Time taken for the ball to hit the ground is 2.47 seconds.
Step-by-step explanation:
Given : A ball is thrown with a slingshot at a velocity of 110 ft./sec. at an angle 20 degrees above the ground from a height of 4.5 ft.
To find : How long does it take for the ball to hit the ground?
Solution :
According to question,
The equation that models the height of the ball in feet as a function of time is
[tex]h(t) = h_0 + v_0t -16t^2[/tex]
Where, [tex]h_0[/tex] is the initial height,
[tex]v_0[/tex] is the initial velocity and
t is the time in seconds.
We have given,
Initial height, [tex]h_0=4.5 ft.[/tex]
A ball is thrown with a slingshot at a velocity of 110 ft./sec. at an angle 20 degrees.
The initial speed, [tex]v_0=110\times \sin(206\circ)[/tex]
[tex]v_0=37.62ft/s[/tex]
We have to find the time for the ball to hit the ground i.e. h(t)=0
Substitute all the values in the formula,
[tex]0 =4.5+ 37.62t -16t^2[/tex]
Applying quadratic formula to solve the equation,
The solution of quadratic general equation [tex]ax^2+bc+c=0[/tex] is
[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
Where, a=-16 , b=37.62 , c=4.5
Substituting in the formula,
[tex]t=\frac{-37.62\±\sqrt{(37.62)^2 -4(-16)(4.5)}}{2(-16)}[/tex]
[tex]t=\frac{-37.62\±\sqrt{1703.2644}}{-32}[/tex]
[tex]t=\frac{-37.62\±41.270}{-32}[/tex]
[tex]t=\frac{-37.62+41.270}{-32},\frac{-37.62-41.270}{-32}[/tex]
[tex]t=-0.114,2.47[/tex]
neglecting the negative value
t=2.47 seconds
Therefore,Option B is correct.
Time taken for the ball to hit the ground is 2.47 seconds.
