Question

EXPLORE A projectile is launched with a launch angle of 30° with respect to the horizontal direction and with an initial speed of 10 m/s. s0 (A) How do the vertical and horizontal components of the projectile's velocity vary with time? 40 35 (B) How long does it remain in flight? 25 (C) For a given launch speed, what launch angle produces the longest time of flight? 15 10 toy CONCEPTUALIZE Consider the projectile to be a point mass that starts with an initial velocity, upward and to the right, with forces from air resistance neglected. There is no force acting horizontally to accelerate its horizontal motion, while its vertical motion is accelerated downward by gravity Therefore, as the projectile moves to the right at a constant rate, the vertical part of its motion consists of first rising upward and then moving downward until the projectile strikes the ground. Use the simulation to display the projectile motion. Angle 回degrees 15 Timc-0.0 CATEGORIZE The velocity has components in both the x- and y- directions, so we categorize this as a problem involving particle motion in two dimensions. The particle also has only a y-component of acceleration, so we categorize it as a particle under constant acceleration in the y-direction and constant velocity in the x-direction. Display in a New Window ANALYZE (A) How do the vertical and horizontal components of the projectile's velocity vary with time? The initial velocity in the x-direction vxo is related to the initial speed by Vxo- vo cos 30° The constant velocity in the x-direction means that the equation describing the time dependence of x for the particle, with xo taken as 0, is x m/s) t. Your response differs from the correct answer by more than 10%. Double check your calculations. The equation for the vertical coordinate, which is constantly accelerating downward at g -9.8 m/s2,s | × m/s) t Your response differs from the correct answer by more than x m/s2) 2. Make sure your use of signs and directions 10%. Double check your calculations. + is consistent with the usage in the textbook. FINALIZE The- t2 term is negative. The other time-dependent term is proportional to t and positive, which of the two dominates at small t? Which term's magnitude gets larger faster as t gets large? What effect does that have on the sign of the y-coordinate as t starts out small and then gets larger? Is this consistent with the path you expect the projectile to take?

Answer 1

t 46-374 314 Vo 26.87% с) u.zb,-26.8伏め39.20.882 m/s C3446 20.9%