Help me for Physics, please?

Please help with General Physics question?

• Hey you guys can you please help me with this Physics questions??? If you don't the answer to all just answer the one you can. If at all possible could you please show me how you completed the question...?? PLEASE DO NOT JUST ANSWER TO GET POINTS OR PUT," FIGURE IT OUT"..THAT REALLY DOES NOT HELP PEOPLE AT ALL. ITS PHYSICS NOT ELEMENTARY MATH. IF I COULD FIGURE IT OUT MYSELF I WOULDN'T BE ON HERE! THANX AGAIN :) 1.) A hockey puck slides off the edge of a table with an initial velocity of 26.0 m/s. The height of the table above the ground is 2.00 m. What is the angle below the horizontal of the velocity of the puck just before it hits the ground? a. 12.8° b. 13.5° c. 31.8° d. 77.2° e. 72.6° 2. A ball is thrown at a 60.0° angle above the horizontal across level ground. It is released from a height of 2.00 m above the ground with a speed of 16.0 m/s. How long does the ball remain in the air before striking the ground? a. 2.05 s b. 2.96 s c. 2.82 s d. 1.80 s e. 16.2 s 3. A child throws a ball with an initial speed of 8.00 m/s at an angle of 40.0° above the horizontal. The ball leaves her hand 1.00 m above the ground. How long is the ball in flight before it hits the ground? a. 9.14 s b. 6.79 s c. 2.44 s d. 1.22 s e. 7.45 s

• Answer:

  1. horizontal velocity = horizontal distance /time = 26m/s initial vertical velocity = 0m/s d = v0 t + 1/2 at^2 -2m = 0*t + 1/2 (-9.81 m/s^2) *t^2 t = 0.63855 s vertical final velocity = v0 + at = (9.81*0.63855) = 6.264 m/s angle = arctan ( vertical velocity/ horizontal velocity) = arctan ( 6.264/26) = 13.5 deg 2. d = v0t + 1/2 at^2 -2 m = 16 sin 60 -(1/2 *9.81 * t^2) t = 1.8 s 3. vf =v0 + at vf = 0 at the highest point 0 = 8 sin 40 + -9.81t t = 0.524 s d = v0t + 1/2 at^2 d = (8sin40*0.524) -(1/2 *9.81*0.524^2) d = 1.348 m the total height is 2.348 m, the initial velocity is zero since this is at the highest point 2.348 m = v0t + 1/2 at^2 -2.348 = -9.81*1/2*t^2 t = 0.69 s total time = 0.69 + 0.524 = 1.215 s =1.22s