Answer:
This is because we are surrounded by positive ions from electromagnetic fields generated by computers, cell phones, and other electronic devices which can impair brain function and suppress the immune system causing symptoms such as: anxiety, breathing difficulty, fatigue, headaches, irritability, lack of energy, poor concentration, nausea, and vertigo,
Explanation:
Given :
A 120 kg box is on the verge of slipping down an inclined plane with an angle of inclination of 47º.
To Find :
The coefficient of static friction between the box and the plane.
Solution :
Vertical component of force :

Horizontal component of force(Normal reaction) :

Since, box is on the verge of slipping :

Therefore, the coefficient of static friction between the box and the plane is 1.07.
Hence, this is the required solution.
Answer:
The final velocity of the ball is 39.2 m/s.
Explanation:
Given that,
A ball is dropped from rest from a high window of a tall building.
Time = 4 sec
We need to calculate the final velocity of the ball
Using equation if motion

Where, v = final velocity
u = initial velocity
g = acceleration due to gravity
t = time
Put the value into the formula


Hence, The final velocity of the ball is 39.2 m/s.
The frictional force is always act in opposite direction of motion. if wheels is moving in +x axis or right then the f force is act in -x or left