2. A roller coaster at an amusement park has a dip that bottoms out in a vertical circle of radius r. A passenger feels the seat of the car pushing upward on her with a force equal to five times her weight as she goes through the dip. Of r = 21.5 m, how fast is the roller coaster traveling at the bottom of the dip?

Several teenagers swim toward a rectangular, wooden raft that is 2.00 m wide and 2.50 m long. If the raft is 9.80 cm thick, how many 75.0 kg teenage boys can stand on top of the raft without the raft becoming submerged? Assume the wood density is 650 kg/m3.

A sea breeze occurs because warm air rises on land and moves toward the ocean to cool. The cool air then moves from the ocean to be warmed by the land. a. True
b. False

The change in pitch of a train's horn as it passes while you are standing still can be explained bya. sympathetic vibration.
b. ultrasonic vibrations.
c. resonance.
d. the Doppler effect.

Stratovolcanoes can become larger than a cinder cone volcanoes because ?A. Earthquakes aren’t associated with stratovolcanoes

B. Stratovolcanoes are the result of hardened pyroclastic flows

C. The layers of pyroclastic Deposits are alternated with layers of viscous lava

D. The temperature of the lava associated with stratovolcanoes is lower than the lava associated with Cindercone volcanoes

A wave with a period of 1/3 second has a frequency of

a boeing 747 has a total mass, including passengers and luggage, of 250,000 kg. How much force do the engines supply to achieve a take off velocity of 990 m/s in 35 seconds.