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A 7-kg rifle is used to fire a 10-g bullet that travels with a speed of 700 m/s. (a) What is the speed of recoil of the rifle? (b) How much energy does it transmit to the shoulder of the person using the rifle as it stops?
Result: (a) -1.0 m/s (b) 35 J
A cliff is 20m above the ground. A boy rolls a ball off the edge with an unknown initial velocity, and its strikes the ground 3m horizontally away. Calculate the initial velocity of the ball
Quincy Quarterback is doing a NFL tryout. He is trying to impress the observers
with his magnificent arm. He can generate a maximum resultant velocity of 19
m/s with his arm. Determine the optimum release angle to maximize throwing
distance. Assume that the ball is release 2.1 m above the ground, and that the ball
hits the ground (it is not caught).
A Cliff Calamity is going to attempt a dive into the surf. This no simple dive, but
a cliff dive from the maximum allowable competitive height of 28 m (about 92
feet). Complicating the dive is some rocks in the surf for about 7 m horizontally
from the cliff face. Cliff takes off from the cliff with a vertical velocity of 0 m/s
and a horizontal velocity of 3.5 m/s. Does cliff clear the rocks? What is Cliff’s
vertical velocity at the instant of impact?
The distance from the pitcher’s mound to home plate is 60 feet 6 inches (18.44
m). The fastest recorded pitch is 104.8 mph (46.85 m/s). If the pitch was thrown
with a release angle of 0o relative to the horizontal, what is the vertical
displacement of the ball between ball release on the mound and home plate?
Assume the ball is released 18.44 m from home plate.
A skydiver steps out of a perfectly good airplane. How far did the skydiver
fall in 5 sec? What was the skydiver’s velocity after 5 sec? Create
position-time, velocity-time, and acceleration-time curves for the first five
sec of the fall. (Assume no other influences are acting on the skydiver,
acceleration due to gravity is –10 m/s2, and start at time 0 with 0.25-sec
increments for the plots.)
The length of the object is 18.2+or-0.01cm Estimate the percentage error this measurement
End of A of a uniform rod AB of weight W and length a is hinged freely to a vertical wall B is connected to C on the wall by a light inextensible string of length a c is at b distant above A show the reaction of hinge at A is w/4b √[a²+8b²]
A source emitting sound at 385.0Hz is moving toward an observer at 32.0 m/s . The air temperature is 20.3C. What is the frequency of the sound detected by the observer?
The air temperature is 24C and an air column carries a standing sound wave at a frequency of 350Hz. What is the length of the air column, which is closed at one end, if you want to hear the third harmonic ?
