Answer:
The drum drill is just one option in stride frequency development. Most of the time, the drum drill can be seen as just a rhythm drill that allows an athlete to relax and experiment with the right range of motion and bounce. A solid background in floating drills and developing reactivity should help athletes mold their stride into a balanced motion that maximizes their speed.
I have used frequency drills for years and now understand the nature of stride development mainly from shaping the stride parameters we all have known about for a long time. The drum drill is a special exercise that can make a great change in athletes who are receptive to improving and with a coach who is worth their salt in instruction. The drum drill is just one option for improving an athlete, and it’s more than fine to use any method you see fit that helps improve stride frequency.
Explanation:
Answer:
C) 464 N
Explanation:
The equation of the forces acting on the skydiver is:

where
(mg) is the weight of the skydiver, acting downward, with
m being the mass of the skydiver
g is the acceleration of gravity
R is the air resistance, acting upward
a is the acceleration of the skydiver
In this problem:
m = 80 kg
g = 9.8 m/s^2
a = 4.0 m/s^2
Solving the equation for R, we find the force of air resistance:

Answer:
a) 230 Km b) 76.7 km/h c) Please see below
Explanation:
a) If we can neglect the time while the driver accelerated, the movement can be divided in two parts, each of them at a constant speed:

⇒ 
b) The average x component of velocity, can be calculated applying the definition of average velocity, as follows:

If we choose t₀ = 0 and x₀ = 0, replacing xf and t by the values we have already found, we can find vavg,x as follows:

c) The found value of avg,x is not the same as the arithmetic average of the initial and final values of vx (70 Km/h) due to the time traveled at both velocities was not the same.
If the driver had droven half of the time (1.5 h) at 50 km/h and the other half at 90 km/h, total displacement would have been as follows:

Applying the definition of average velocity once more:

which is the same as the arithmetic average of the initial and final values of vₓ.
It’s decreasing as environmental cause osmosis