A 30.0-kg packing case is initially at rest on the floor of a1500-kg pickup truck. The coefficient of static friction betweenthe case and the truck floor is 0.30 and the coefficient of kineticfriction is 0.20. Before each acceleration given below, the truckis traveling due north at constant speed.(a) Find the magnitude and direction of thefriction force acting on the case when the truck accelerates at2.51 m/s2 northward. magnitude Ndirection (b) Find the magnitude and direction of the friction force actingon the case when the truck accelerates at 3.63 m/s2 southward. magnitude Ndirection

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 10.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.90 m/s; (b) he is then lifted at the constant speed of 4.90 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 68.0 kg rescue by the force lifting him during each stage?

Will give brainliest! which statement best describes the difference between strong nuclear forces and weak nuclear forces? weak nuclear forces are involved when certain types of atoms break down. strong nuclear forces are responsible for holding atoms' nucleus together. weak nuclear forces hold bonds between atoms together. strong nuclear forces hold together the nucleus of an atom. strong nuclear bonds prevent atoms from falling apart. weak nuclear bonds prevent compounds from falling apart. strong nuclear forces are involved in breaking electrons from their shells. weak nuclear forces hold protons in the nucleus.

This is the substance(s) formed in a chemical reaction.