A 5 kg book is held 20 m above the floor. How much gravitational potential energy does it have?*

(* USE 10 /s2 as the acceleration due to gravity)

a 100 J
b 4 J
c 1000 J
d 98 J

Identify the type of synthetic material used in each object

Determine the fraction of the magnitude of kinetic energy lost by a neutron (m1 = 1.01 u) when it collides head-on and elastically with a target particle at rest which is 21h (heavy hydrogen, m = 2.01 u).

Aboat radioed a distress call to a coast guard station. at the time of the call, a vector a from the station to the boat had a magnitude of 45.0 km and was directed 15.0° east of north. a vector from the station to the point where the boat was later found is = 30.0 km, 15.0° north of east. what are the components of the vector from the point where the distress call was made to point where the boat was found? in other words, what are the components of vector c = b - a?