In the hammer throw, an athlete spins a heavy mass in a circle at the end of a c
ID: 1641226 • Letter: I
Question
In the hammer throw, an athlete spins a heavy mass in a circle at the end of a cable before releasing it for distance as shown in (Figure 1) . For male athletes, the "hammer" is a mass of 7.3 kgat the end of a 1.2 m cable, which is typically a 3.0-mm-diameter steel cable. A world-class thrower can get the hammer up to a speed of 29 m/s. If an athlete swings the mass in a horizontal circle centered on the handle he uses to hold the cable.
What is the tension in the cable? Neglect the gravity.
How much does the cable stretch? Young modulus for steel is 20×1010N/m2.
Explanation / Answer
(a) tension in the cable is equal to the centripetal force is
F = m*v^2/r
= 7.3*(29)^2/1.2
F = 5116.083 N = 5120 N
(b) tension = 5120 N,
youngs modulus = 20*10^10 N/m^2
lenght = 1.2 m
Radius = diameter/2
= 3 mm/2 = 1.5 mm
= 1.5*10^-3 m
youngs modulus = F*l/A*del_l
del_l = 5120 N * 1.2 m / 20*10^10 * (3.14)*(1.5*10^-3)^2
= 43.48*^10-4 m
del_l = 4.348 mm
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.