An appliance requires 100 joules of energy and gives out 50 joules of energy. What is the percent efficiency? Please show work 15 points

(01.02 mc) nicole pushes her bike up a hill. overhead, the sun exerts a gravitational force on earth. which statement is true about the bike and earth? they both experience contact forces. they both experience non-contact forces. the bike experiences a non-contact force and earth experiences a contact force. the bike experiences a contact force and earth experiences a non-contact force. they both experience non-contact forces.

How many neutrons does element x if it’s atomic number is 28 and its mass number is 87

Explain what will happen if decomposers were apsent from a forest ecoysystem.