H 3.4 1 point possible (graded) An airplane flying horizontally with a speed of 600 km/h at a height of 900 m drops a crate of supplies (see the following figure). If the parachute fails to open, how far (in meters) in front of the release point does the crate hit the ground? Enter your answer to two significant figures without units. vkm/h 2258.77 Answer: 2258.77 H 3.5 3 points possible (graded) A projectile is launched at an angle of 33° and lands 21 s later at the same height as it was launched. a. What is the initial speed (in m/s) of the projectile? Give your answer to two significant figures without units. 188.93 Answer: 188.93 b.What is the maximum altitude (in m) ? Give your answer to two significant figures without units. 540.23 Answer: 540.23 b.What is the range (in m) ? Give your answer to two significant figures without units. 3327.41 Answer: 3327.41 H 3.6 1 point possible (graded) A mountain biker encounters a jump on a race course that sends him into the air at 60 degrees to the horizontal. If he lands at a horizontal distance of 17 m and 19 m below his launch point, what is his initial speed (in m/s) ? Enter your answer to two significant figures without units. 10.81 Answer: 10.81 H 3.7 1 point possible (graded) A fairground ride spins its occupants inside a flying saucer-shaped container. If the horizontal circular path the riders follow has an 7 m radius, at how many revolutions per minute are the riders subjected to a centripetal acceleration equal to that of gravity? Enter your answer to two significant figures without units. 11.3 Answer: 11.3
H 3.8 1 point possible (graded) The driver of a car moving at 86 km/h presses down on the brake as the car enters a circular curve of radius r=269 m. If the speed of the car is decreasing at a rate of 9.0 km/h each second, what is the magnitude of the acceleration in m/s2 of the car at the instant its speed is 52 km/h? Enter your answer to two significant figures without units. 2.62 Answer: 2.62 H 3.9 1 point possible (graded) An elephant is located on Earth's surface at a latitude À. Calculate the centripetal acceleration de of the elephant resulting from the rotation of Earth around its polar axis. Hint: express your answer in terms of À, the radius Rg of Earth, and time T for one rotation of Earth. If À = 40", find the ratio de and enter your answer to two significant digits without units. The radius of Earth is Rg = 6400 km. Equator 0.0026 Answer: 0.0026