In the javelin throw at a track-and-field event, the javelin is launched at a speed of 28 m/s at an angle of 39° above the horizontal. As the javelin travels upward, its velocity points above the horizontal at an angle that decreases as time passes. How much time is required for the angle to be reduced from 39° at launch to 17°?
2006-09-18 15:39:49 · 3 answers · asked by gabison930 1 in Science & Mathematics ➔ Physics
Since movement in X (horizontal motion) is not affected by gravity (remember Newton's 1st law), you can do this:
(1) Vx = 28 cos (39º)
(2) Find cos (17º)
(3) (1)/(2) = time required.
2006-09-18 16:18:49 · answer #1 · answered by Calculus Teacher 2 · 0⤊ 0⤋
the respond is B. formerly the collision, you're vacationing in a straight away line, with the automobile pushing you forward. in the process the turn, your physique tries to maintain its forward momentum, yet you're contacted by making use of the automobile door by way of fact the automobile moved in the process the turn. The door (collision) then exerts a leftward rigidity on you, inflicting you to pass in that direction with the automobile. it incredibly is termed centripetal rigidity.
2016-10-01 03:18:04 · answer #2 · answered by ? 4 · 0⤊ 0⤋
Draw vectors and solve yourself.
2006-09-18 16:14:04 · answer #3 · answered by astrokid 4 · 0⤊ 0⤋