Answer:
The height of Sears Tower is 1448.5 feet.
Explanation:
<h3>
We apply the free fall formula to the ball:
</h3><h3>
</h3><h3>y: The vertical distance the ball moves at time t </h3><h3>
i: Initial speed
</h3><h3>g=Gravity acceleration=
</h3>
Known information
We know that the vertical distance (y) that the ball moves in 9,5s is equal to height of Sears Tower (h).
Too we know that the ball is released from rest, then,
=0
Height of Sears Tower calculation:
We replace in the equation 1 the data following;
Answer: The height of Sears Tower is 1448.5 ft
m = mass of the person = 82 kg
g = acceleration due to gravity acting on the person = 9.8 m/s²
F = normal force by the surface on the person
f = kinetic frictional force acting on the person by the surface
μ = Coefficient of kinetic friction = 0.45
The normal force by the surface in upward direction balances the weight of the person in down direction , hence
F = mg eq-1
kinetic frictional force on the person acting is given as
f = μ F
using eq-1
f = μ mg
inserting the values
f = (0.45) (82) (9.8)
f = 361.6 N
Answer:
The cartilage is the structure that reduces friction between joints.
Explanation:
Cartilage is the tissue between the bone joints. They are composed of several membranes and cellular groups. One of them called synovial membrane which provides lubricant to the edges of tissue that are touched by the bones. Reducing the friction and absorbing it so the body can move without obstacles.
