Lighting gives a sense of scale (The sky)
Answer:
F = 9.81 [N]
Explanation:
To solve this problem we must use Newton's third le which tells us that the sum of forces on a body that remains static must be equal to one resulting from these forces in the opposite direction.
Let's perform a summation of forces on the vertical axis-y to determine the normal force N.
∑F = 0 (axis-y)

where:
m = mass = 4 [kg]
g = gravity acceleration = 9.81 [m/s²]
![N - (4*9.81)=0\\N = 39.24 [N]](https://tex.z-dn.net/?f=N%20-%20%284%2A9.81%29%3D0%5C%5CN%20%3D%2039.24%20%5BN%5D)
Now we know that the frictional force can be calculated using the following equation.
f = μ*N
where:
f = friction force [N]
μ = friction coefficient = 0.25
N = normal force = 39.24 [N]
Now replacing:
![f = 0.25*39.24\\f = 9.81[N]](https://tex.z-dn.net/?f=f%20%3D%200.25%2A39.24%5C%5Cf%20%3D%209.81%5BN%5D)
Then we perform a sum of forces on the X-axis equal to zero. This sum of forces allows us to determine the minimum force to be able to move the object in a horizontal direction.
∑F = 0 (axis-x)
![F-f=0\\F-9.81=0\\F= 9.81[N]](https://tex.z-dn.net/?f=F-f%3D0%5C%5CF-9.81%3D0%5C%5CF%3D%209.81%5BN%5D)
If the coefficient was smaller, a smaller force (F) would be needed to start the movement, this can be easily seen by replacing the value of 0.25, by smaller values, such as 0.1 or 0.05.
If the coefficient were larger, a larger force would be needed.
What is the SI (metric) unit of FORCE?
with symbol ( N )
All the best !
Answer:
x = -6.5 meters
Explanation:
The position of a ball as a function of time t is given by :
..................(1)
Where t is time in seconds
We need to find the position of the ball at 1.9 s. It can be simply calculated putting t = 1.9 s in equation (1) as :

x = -6.5 meters
So, the position of the ball at 1.9 seconds is -6.5 meters. Hence, this is the required solution.
Answer:
The dilation of time.
The falling of objects.
The changing of paths of light.
Explanation:
I have explained in the image attached below.
From the explanation, the correct ones are;
The dilation of time.
The falling of objects.
The changing of paths of light.