Acrate is located in the center of a flatbed truck. the truck accelerates to the east and the crate moves with it, not sliding at all. what is the direction of the friction force exerted by the truck on the crate?

British cologoinst admisitrion

The radiation of the fire causes the saucepan to heat up. the conduction of the saucepan then to distribute the heat over the saucepan and to give heat to the water. the convection of the water distributing the heat within the water, till all the water is boiling