The first hill of a roller coaster is 42.0 meters high. The roller coaster drops to a height of 4.2 meters above the ground at the bottom of this first hill. If the mass of the roller coaster is 34,500 kg, what is the velocity at the bottom of the first hill? Ignore friction and assume the velocity at the top of the first hill is 0 m/s.

Ineed with these last two questions: 1) what are two types of cold air masses that influence the weather in north america? name them and describe their humidity. 2) describe the motion of a cold air mass and a warm air mass and the weather you would expect at a warm front and an occluded front.

Acamcorder has a power rating of 20 watts. if the output voltage from its battery is 9 volts, what current does it use?

1. explain how you calculate the net force in any direction on the box. 2. suppose an upward force of 15n is added to the box. what will be the net vertical force on the box? 3. what force could be applied to the box to make the net force in the horizontal direction zero? explain. 4. suppose a force of 25n to the right is added to the box. what will be the net force to the right?