10-kg mass at rest on a horizontal frictionless table is accelerated by a force of 20 N. How much work is needed to accelerate the ball to a welocity of 10 m/s?
(A) 5 j
(B) 200j
(C) 500j
(D) 2000j

Asample of a gaseous substance changes into a liquid

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )

Which statement correctly describes the interaction between magnetic poles? north and south poles attract each other. north and south poles repel each other. two north poles will attract each other. two south poles will attract each other.