Respuesta :
Answer:
The speed and height at 0 sec are 20 m/s and 0 m.
The speed and height at 1 sec are 10.2 m/s and 15.1 m.
The speed and height at 2 sec are 0.4 m/s and 20.4 m.
The speed and height at 3 sec are 9.4 m/s and 15.9 m.
The speed and height at 4 sec are 19.2 m/s and 1.6 m.
Explanation:
Given that,
Initial speed = 20 m/s
Suppose, given time in charge are t= 0, 1, 2, 3, 4 sec
At t=0 sec,
We need to calculate the velocity and height
Using equation of motion
[tex]v=u-gt[/tex]
Put the value into the formula
[tex]v=20-9.8\times0[/tex]
[tex]v=20\ m/s[/tex]
Now, using second equation of motion
[tex]h=ut-\dfrac{1}{2}gt^2[/tex]
Put the value into the formula
[tex]h=20\times 0-\dfrac{1}{2}\times9.8\times0[/tex]
[tex]h=0\ m[/tex]
At t=1 sec,
We need to calculate the velocity and height
Using equation of motion
[tex]v=u-gt[/tex]
Put the value into the formula
[tex]v=20-9.8\times1[/tex]
[tex]v=10.2\ m/s[/tex]
Now, using second equation of motion
[tex]h=ut-\dfrac{1}{2}gt^2[/tex]
Put the value into the formula
[tex]h=20\times1-\dfrac{1}{2}\times9.8\times1^2[/tex]
[tex]h=15.1\ m[/tex]
At t=2 sec,
We need to calculate the velocity and height
Using equation of motion
[tex]v=u-gt[/tex]
Put the value into the formula
[tex]v=20-9.8\times2[/tex]
[tex]v=0.4\ m/s[/tex]
Now, using second equation of motion
[tex]h=ut-\dfrac{1}{2}gt^2[/tex]
Put the value into the formula
[tex]h=20\times2-\dfrac{1}{2}\times9.8\times2^2[/tex]
[tex]h=20.4\ m[/tex]
At t=3 sec,
We need to calculate the velocity and height
Using equation of motion
[tex]v=u-gt[/tex]
Put the value into the formula
[tex]v=20-9.8\times3[/tex]
[tex]v=-9.4\ m/s[/tex]
Negative sign shows the opposite direction of motion
Now, using second equation of motion
[tex]h=ut-\dfrac{1}{2}gt^2[/tex]
Put the value into the formula
[tex]h=20\times3-\dfrac{1}{2}\times9.8\times3^2[/tex]
[tex]h=15.9\ m[/tex]
At t=4 sec
We need to calculate the velocity and height
Using equation of motion
[tex]v=u-gt[/tex]
Put the value into th formula
[tex]v=20-9.8\times4[/tex]
[tex]v=-19.2\ m/s[/tex]
Negative sign shows the opposite direction of motion
Now, using second equation of motion
[tex]h=ut-\dfrac{1}{2}gt^2[/tex]
Put the value into the formula
[tex]h=20\times4-\dfrac{1}{2}\times9.8\times4^2[/tex]
[tex]h=1.6\ m[/tex]
So, The ball has hit the ground at 5 sec.
Hence, The speed and height at 0 sec are 20 m/s and 0 m.
The speed and height at 1 sec are 10.2 m/s and 15.1 m.
The speed and height at 2 sec are 0.4 m/s and 20.4 m.
The speed and height at 3 sec are 9.4 m/s and 15.9 m.
The speed and height at 4 sec are 19.2 m/s and 1.6 m.
