Use the inverse square law, thus if you move a distance of 3m away, the sound intensity decrease by 1/3^2= 1/9
acceleration = change in velocity /change in time
convert 40km to meter then divide it with 5
Step 1 : Get your supply list together
Step 2 : Pick what model you want to do
Step 3 : Ask for a partner
Step 4 : Complete the model and take your time.
Step 5 : Read the directions carefully