Grandma henderson challenges michael johnson in the 400-meter dash. grandma h spins her wheelchair wheels 5 times and gives up 15 meters from the starting line. mj makes a complete circle around the track and stops at the starting line. in this race who has the greatest average speed?

You are your friend move a new refrigerator into his kitchen. you apply a horizontal force of 252 n in the negative x direction to try and move the 56 kg refrigerator. the coefficient of static friction is 0.61. (a) how much static frictional force does the floor exert on the refrigerator? give both magnitude (in n) and direction. magnitude n direction (b) what maximum force (in n) do you need to apply before the refrigerator starts to move?