811 The following median grain size data were obtained durin

8.11. The following median grain size data were obtained during the isothermal liquid phase sintering of an 82W-8Mo- 8Ni-2Fe alloy. time, min 30 120 480 960 grain size, m 6.0 13.4 21.3 31.6 What is the time dependence for grain growth in the system and what is the

Solution

A 0.200 kg dart is fired horizontally at a speed of 2.75 m/s when it hits a 0.700 kg block of wood suspended by a string. The nose of the dart sticks into 0.00210 m the wood. Together the dart and block swing upwards from a height of 0.0500 m above a table to 0.128 m above the table. Which of the following is the average force the dart applies to the block during impact?

a. 32.4 N

b. 15.1 N

c. 1.36 N

d. 0.872 N