1.A 580 g squirrel with a surface area of 950 cm² falls from a 7.2 m tree to the
ID: 1332550 • Letter: 1
Question
1.A 580 g squirrel with a surface area of 950 cm² falls from a 7.2 m tree to the ground. Estimate its terminal velocity. (Use the drag coefficient of a horizontal skydiver found in the table of section 5.2 of OpenStax College Physics. Also use the density of air and other information found in that section.)
a) m/s
What will be the velocity of a 58 kg person hitting the ground after falling from that height, assuming no drag contribution in such a short distance?
b) m/s
2).A 7.7 cm section of spine is subjected to a compression force of 600 N. Find the magnitude of its change in length, taking the Young's modulus to be 4.9×108 N/m² and approximating the spine as a cylinder 3.9 cm in diameter.
cm.
Explanation / Answer
(a) We know that when terminal velocity is reached then the net force will be zero on the object
therfore
Gravity force = Drag force + buoyancy force
gravity force = mass*acceleration due to gravity = 0.580*9.81
Drag force = (1/2)Cd*p*A*V2
where p is density of air , A is area and V is the terminal velocity
Buoyancy force = pgv where p is density of air , g is acceleration due to gravity and v is the volume of squirrel
0.580*9.81 = (1/2)Cd*p*950*10-4V2 + p*9.81*950*10-4
(v = area*length (here length is not mentioned therefore taking its unity))
We will solve this by using values of Cd (coefficient of drag ,p (density of air))from the given table.
(b) In this case we have not taken any drag force therefore we will apply the equation of motion
Height is 7.2 m
V2 =2*9.81*7.2
V = 11.885 m/s
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.