A toy airplane is flying in a straight horizontal (parallel to the ground) path with a speed of vi=33 m/s. Suddenly, the airplane's engines stop (at t=0). Using an x axis that is horizontal and along the plane's original velocity and a y axis that is vertical with positive away from the ground, the airplane now has an acceleration given by the following expressions: ax(t)=−t2/C ay(t)=−g[1−vx(t)/vi] where C=2690s4/m and vx(t) is the x component of the airplane's velocity. The airplane crashes 34.87 seconds after the engines stop.

Imagine you are riding on a yacht in the ocean and traveling at 20 mph. you then hit a golf ball at 100 mph from the deck of the yacht. you see the ball move away from you at 100mph, while a person standing on a near by beach would observe your golf ball traveling at 120 mph (20 mph + 100 mph). now imagine you are aboard the hermes spacecraft traveling at 0.1c (1/10 the speed of light) past mars and shine a laser from the front of the ship. you would see the light traveling at c (the speed of light) away from your ship. according to einstein’s special relativity, how fast will a person on mars observe the light to be traveling? a) 0.1c (1/10 the speed of light) b) c (the speed of light) c)1.1c (c+0.1c)

Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.

Panel bc in fig. p2.76 is semi-circular, with the 3 meter radius and horizontal straight edge through point b. compute (a) the hydrostatic force of the water on the panel, (b) its center of pressure, and (c) the moment of this force about point b. assume atmospheric pressure on the dry side of the panel