Explanation:
It is given that,
Mass of the runner, m = 70 kg
Length of the tendon, l = 15 cm = 0.15 m
Area of cross section, 
Part A,
Let the runner's Achilles tendon stretch if the force on it is 8.0 times his weight, F = 8 mg
Young's modulus for tendon is, 
The formula of the Young modulus is given by :



Part B,
The fraction of the tendon's length does this correspond is given by :


Hence, this is the required solution.
Momentum = mass x acceleration
5 x 2 = 10 kg. m/s
Answer:

Explanation:
Apparent frequency that is received to the speeder is given as


here we know that

now we have


now the frequency that is received back from the speeder is given as



So difference is the frequency is given as


Answer:
9.66 x 10^-6 m
Explanation:
Use the Wein's displacement law

Where, b is the Wein's constant
b = 2.898 x 10^-3 meter-kelvin
So, λm x 300 = 2.898 x 10^-3
λm = 9.66 x 10^-6 m