Akito pushes a wheelbarrow with 800 W of power. How much work is required to get the wheelbarrow across the yard in 12 s? Round
2 answers:
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Answer: 52 kg skydiver: 9.09 m/s and 522.55 s
95 kg skydiver: 12.3 m/s and 386.2 s
Explanation: <u>Drag</u> <u>Force</u> is an opposite force when an object is moving in a fluid.
For skydivers, when falling through the air, the forces acting on it are gravitational and drag forces. At a certain point, drag force equals gravitational force, which is constant on any part of the planet, producing a net force that is zero. Since there is no net force, there is no acceleration and, consequently, velocity is constant. When that happens, the person reached the <u>Terminal</u> <u>Velocity</u>.
Drag Force and Velocity are proportional to the squared speed. So, terminal velocity is given by:
where
m is mass in kg
g is acceleration due to gravitational force in m/s²
ρ is density of the fluid in kg/m³
C is drag coefficient
A is area of the object in the fluid in m²
Calculating:
The 52kg skydiver has terminal velocity of:
9.09
The 95kg skydiver's terminal velocity is
12.3
The 52 kg and 95kg skydivers' terminal velocity are 9.09m/s and 12.3m/s, respectively.
The time each one will reach the floor will be:
52 kg at 9.09 m/s:
t = 522.5
95 kg at 12.3 m/s:
t = 386.2
The 52 kg and 95kg skydivers' time to reach the floor are 522.5 s and 386.2 s, respectively.
Answer:
The beam of light is moving at the peed of:
km/min
Given:
Distance from the isalnd, d = 3 km
No. of revolutions per minute, n = 4
Solution:
Angular velocity, (1)
Now, in the right angle in the given fig.:
Now, differentiating both the sides w.r.t t:
Applying chain rule:
Now, using and y = 1 in the above eqn, we get:
Also, using eqn (1),
