What is the mass number of a potassium atom that has 20 neutrons

A12-kg bag of groceries is tossed onto a table at 4.0 m/s and slides to a stop in 2.2 s . modify the equation fδt=δ (mv) to find the force of friction.

Which terms describe the purpose of antennas on devices that use radio waves? transmit and receivemodify and amplifyamplify and receivemodify and transmit

Abike rider starts from rest and accelerates 28.0 meters down a slope in 5.00 seconds. what is her acceleration? select one: a. 3.21 m/sec2 b. 1.75 m/sec2 c. 9.80 m/sec2 d. 2.24 m/sec2