A 61-kg acrobat must jump high and land on his brother's shoulders. To accomplish this, he leaps from a crouched position to a height where his center of mass is 1.20 m above the ground. His center of mass is 400 mm above the ground in the crouch and 900 mm above the ground when his feet leave the ground. What is the average force exerted on him by the ground during the jump?

Two models of the same compound are shown. in what way is model b better than model a? model b shows the types of elements in the compound, but model a does not. model b shows the three-dimensional shape of the molecule, but model a does not. model b shows how the atoms in the molecule are connected, but model a does not. model b shows the number of atoms of each element in the molecule, but model a does not