{13.14} What is the magnitude of its angular momentum? Determine the force exerted by the rope on her arms?

A car of mass 1000kg moves with a speed of 50 m/s on a circular track of radius 100m. What is the magnitude of its angular momentum (in kg.m^2/s) relative to the center of the racetrack? ============================================== Answers: a) 5 x 10^2 b) 5 x 10^6 c) 2.5 x 10^6 d) 2.5 x 10^4 ################################################# A 50 kg ice skater is moving at 5 m/s when she grabs the loose end of a rope, then opposite end of which is tied to a pole. She then moves in a circle of radius 1m around the pole. Determine the force exerted by the rope on her arms. ============================================== a) 1250 N b) 250 N c) 50 N d) 1100 N =======================... click for more

(1.9) magnitude of vector, height of the arrow at a point 150 meters downrange

If A = (12i - 16j) and B = (-24i+10j), what is the magnitude of the vector C=(2A-B)? =================================================== Answers: a) 42 b) 22 c) 64 d) 90 ################################################### An archer shoots an arrow with a velocity of 45 m/s at an angle of 50 degrees with the horizontal. What is the height of the arrow at a point 150 meters downrange? ============================================ Answers: a) 4.7 m b) 47.0 m c) 5.6 m d) 56.0 m ================================================== OTA: Please take this problem only if you can show step by step problem solving and equations used. Thank you.

(3.10) angular accelleration of this wheel? Find tension in the string?

At t=0, a wheel rotating about a fixed axis at a constant angular acceleration has an angular velocity of 2 rad/s. Two seconds later it has turned 5 complete revolutions. What is the angular acceleration of this wheel? ============================================== Answer: a) 17 rad/s^2 b) 14 rad/s^2 c) 20 rad/s^2 d) 23 rad/s^2 ################################################# A 9.00 kg hanging weight is connected to a string over a pulley to a 5.00 kg block that is sliding on a flat table. If the coefficient of kinetic friction is 0.15, find the tension in the string. ============================================= Answer: a) 28.3 N b) 36.2 N c) 40.4 N d) 53.4 N ===============... click for more

coefficient of static friction

I'm doing an experiment of coefficient of static friction, and I don't understand it. I'm to place a coin at one edge of the textbook and slowly lift the book. just starts to slip down the incline. when this cccurs,measur the angle(0) I did this.next I'm suppose to fine Ff=m.g.sin0 and N=m.g.cos0. case1=Us for one coin and Case2=Us for stack of coin. Ff=Us.N Us=tan0=? How am I to know the mass of the coin(m),gravity(g),and the angle(0) the flate surface makes with the table: Ff=m.g.sin) and N=m.g.cos)

A spring-loaded cannon

6.) A spring-loaded cannon aimed at 47 degrees above the horizontal is on the last car of a long train of flat cars. The train has an initial velocity of 54.3 km/h. At the moment the train begins to accelerate forward at 0.325 m/s2 , the cannon fires a projectile at 180 m/s. The cannon points in the direction that the train is moving. a.) What is the horizontal range observed by a person standing on the ground? b.) How far on the train from the cannon does the projectile land? Neglect air resistance.