Good morning.
We have:
Where
j is the unitary vector in the direction of the
y-axis.
We have that
We add the vector
-a to both sides:
Therefore, the magnitude of
b is
47 units.
Answer:
11760 joules
Explanation:
Given
Mass (m) = 75kg
Height (h) = 16m
Required
Determine the increment in potential energy (PE)
This is calculated as thus:
PE = mgh
Where g = 9.8m/s²
Substitute values for m, g and h.
P.E = 75 * 9.8 * 16
P.E = 11760 joules
The time taken to hit the ground is 3.9 s, the range is 18m and the final velocity is 42.82 m/s
<h3>
Motion Under Gravity</h3>
The motion of an object under gravity is the vertical motion of the object under the influence of acceleration due to gravity.
Given that a ball is thrown horizontally from the roof of a building 75 m tall with a speed of 4.6 m/s.
a. how much later does the ball hit the ground?
The time can be calculated by considering the vertical component of the motion with the use of formula below.
h = ut + 1/2gt²
Where
- Initial velocity u = 0 ( vertical velocity )
- Acceleration due to gravity g = 9.8 m/s²
Substitute all the parameters into the formula
75 = 0 + 1/2 × 9.8 × t²
75 = 4.9t²
t² = 75/4.9
t² = 15.30
t = √15.3
t = 3.9 s
b. how far from the building will it land?
The range can be found by using the formula
R = ut
Where u = 4.6 m/s ( horizontal velocity )
R = 4.6 × 3.9
R = 18 m
c. what is the velocity of the ball just before it hits the ground?
The final velocity will be
v = u + gt
v = 4.6 + 9.8 × 3.9
v = 4.6 + 38.22
v = 42.82 m/s
Therefore, the answers are 3.9 s, 18 m and 42.82 m/s
Learn more about Vertical motion here: brainly.com/question/24230984
#SPJ1
Answer:
Therefore letter <u>C is the correct answer.</u>
Explanation:
In a projectile motion the total time in the air can be calculated using the following equation:
We analyze the y-component motion.
When the final velocity (v(f)) is equal to zero we calculate the upward time and multiplying it by 2 we find the total time in the air. So we will have:
We can see that the <u>total time is directly proportional to the angle</u>, then when <u>θ increase t increase.</u>
Therefore letter C is the correct answer.
I hope it helps you!
