Answer: 37.981 m/s
Explanation:
This situation is related to projectile motion or parabolic motion, in which the travel of the ball has two components: <u>x-component</u> and <u>y-component.</u> Being their main equations as follows:
<u>x-component:
</u>
(1)
Where:
is the point where the ball strikes ground horizontally
is the ball's initial speed
because we are told the ball is thrown horizontally
is the time since the ball is thrown until it hits the ground
<u>y-component:
</u>
(2)
Where:
is the initial height of the ball
is the final height of the ball (when it finally hits the ground)
is the acceleration due gravity
Knowing this, let's start by finding
from (2):
<u></u>
(3)
(4)
(5)
(6)
Then, we have to substitute (6) in (1):
(7)
And find
:
(8)
(9)
(10)
On the other hand, since we are dealing with constant acceleration (due gravity) we can use the following equation to find the value of the ball's final velocity
:
(11)
(12)
(13) This is the ball's final velocity, and the negative sign indicates its direction is downwards.
However, we were asked to find the <u>ball's final speed</u>, which is the module of the ball's final vleocity vector. This module is always positive, hence the speed of the ball just before it strikes the ground is 37.981 m/s (positive).
Option c. are large
Igneous rocks are crystalline solids which are formed after the magma cools. The sizes vary greatly depending on how quickly the magma cooled. The slower the cooling, the larger the crystals in the final rock. They cooled at depth in the crust where they were insulated by layers of rock and sediment.
Answer:
29.16 J
Explanation:
From Hook's law,
W = 1/2(ke²)..................... Equation 1
Where W = work done, k = Spring constant, e = extension.
Given: W = 9 J, e = 0.5 m.
Substitute into equation 1
9 = 1/2(k×0.5²)
Solve for k
k = 18/0.5²
k = 72 N/m.
The work done required to stretch the spring by additional 0.4 m is
W = 1/2(72)(0.4+0.5)²
W = 36(0.9²)
W = 29.16 J.
Answer: Base units
The principal SI units that are used to derive all other SI units are called base units. The base units are the units of fundamental quantities e.g. M L T that is Mass, Length, and Time. All other physical quantities can be written in the fundamental dimension forms. The physical quantities are not measured directly but are build up from the building blocks that are the fundamental quantities which have base units.
If a football player has more mass, they will also have more <u>momentum</u>. This is because mass is directly proportional to momentum.