A man of mass 80kg carries a load of mass 20kg up a vertical ladder of length 6m. what work has he done (Take g= 10ms-2)​

Aball of mass 0.3kg is released from rest at a height of 8m. how fast is it going when it hits the ground? accleration due to gravity is g=9.8m/s

In a particular chemical reaction, the energy of the reactants is 30 kj and the energy of the products is 5 kj. 
 the maximum energy of the system is 40 kj. sketch a potential energy diagram for this reaction. make sure to label the energy of the reactants, the energy of the products, the activation energy, and the enthalpy change for the reaction.

According to piaget’s stages of cognitive development, the child does not differentiate between self and other objects. the child repeats rewarding activities, discovers new ways to get what he or she wants, and may have imaginary friends. which period is described?