Respuesta :
Answer:
a) u = 30.29 m/s
b) t = 2.09 s
Explanation:
given,
velocity = 45 m/s
angle (θ) = 50°
horizontal velocity = 45 cos 50°
time taken to reach 150 m.
times = [tex]\dfrac{150}{45 cos 50^0}[/tex]
t = 5.19 s
a) height of arrow
[tex]s = u t +\dfrac{1}{2}gt^2[/tex]
[tex]s = v sin \theta \times t+\dfrac{1}{2}gt^2[/tex]
[tex]s = 45 sin 50^0 \times 5.19 -\dfrac{1}{2}\times 9.81\times 5.19^2[/tex]
s = 46.78 m
v² - u² = 2 g s
u² = 2 × 9.81 × 46.78
u = 30.29 m/s
b) time taken by the apple = [tex]\dfrac{u}{g}=\dfrac{30.29}{9.81}[/tex]
= 3.09 s
time after which it has to be thrown = 5.19-3.09 = 2.1 s
The initial speed of the apple will be 30.29 m/s.
How to calculate the speed
The following can be deduced from the information given:
Velocity = 45m/s
Angle = 50°
Horizontal velocity = 45cos50° = 28.93°
Time = 150/28.93 = 5.19s
The initial speed will be calculated thus:
From the second law of motion,
s = ut + 1/2gt²
where, g = acceleration due to gravity = 9.81
s = (45sin50° × 5.19) - (1/2 × 9.81 × 5.19²)
s = (45 × 0.766 × 5.19) - 132.12
s = 178.90 - 132.12
s = 46.78m
Since v² - u² = 2gs
Making u the subject of the formula goes thus:
u² = 2 × 9.81 × 46.78
u² = 917.82
u = 30.29m/s
Furthermore, the time taken by the apple will be:
= u/g = 30.29/9.81 = 3.09s
The time after the arrow launch that the apple should be thrown will be:
= 5.19s - 3.09s
= 2.1 seconds.
Learn more about speed on:
brainly.com/question/4931057
