Answer:
when the body is resting N = 246.96 N
when the body is resting on a tilted surface N = 212.12 N.
when the body is in a elevator N = 317.036 N
Explanation:
when the block is resting on a stationary surface the normal force is balanced by the weight of the body.
weight of the body = mg = 25.2×9.8 = 246.96 N
therefore normal force = 246.98 N.
when the block is resting on a tilted surface the normal force will be balanced by the 
component of the weight where Ф is the angle of inclination.
therefore N = mg
N= 212.12 N.
when the block is resting on a elevator that is accelerated upward the normal force will be the sum of weight and force due to acceleration ma
therefore N = 246.98 + 25.2×2.78
N = 317.036 N
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.
Answer:
stress
Explanation:
Common causes of chronic insomnia include: Stress. Concerns about work, school, health, finances or family can keep your mind active at night, making it difficult to sleep. Stressful life events or trauma — such as the death or illness of a loved one, divorce, or a job loss — also may lead to insomnia.
Answer:
The awnser is d
Explanation:
i know cause i took the test
