Recent content by steph35

well, for a) i found t by using t=d/v and got 5.13E-10 s. i found theta by arctan Ay/Ax and i got 27.9 degrees. so then i used yf=yi+(V_yi)t-.5(9.80)t^2 to find the yf and i got 4.67E-3 and it was wrong. for b)i found the velocity unit vectors and i got it wrong. i did Vxi= Vi(cos27.9) and...

all right, i got the t and solved c. however, for a) I am still a bit confused. are they asking for his initial position? because if they are wouldn't it be 0 for ihat and .443 jhat? i got the 0 ihat correct, but the.443 was wrong?

Homework Statement As an example of the manipulation of an electron beam, consider an electron traveling away from the origin along the x-axis in the xy plane with initial velocity v = vi. As it passes through the region x = 0 to x = d, the electron experiences acceleration a = ax + ay, where...

Homework Statement A point on a rotating turntable 21.5 cm from the center accelerates from rest to a final speed of 0.800 m/s in 1.75 s. At t = 1.28 s, find the magnitude and direction of each of the following. Homework Equations (a) the radial acceleration (b) the tangential...

Homework Statement A projectile is fired up an incline (incline angle ϕ) with an initial speed vi at an angle θi with respect to the horizontal. Homework Equations For what value of θi is d a maximum, and what is that maximum value? (Use v_i for vi, phi for ϕ, and g as appropriate. ϕ...

Homework Statement An astronaut on a strange planet finds that she can jump a maximum horizontal distance of 10.0 m if her initial speed is 2.40 m/s. Homework Equations What is the free-fall acceleration on the planet? (Ignore air resistance.) The Attempt at a Solution So in order to...

Homework Statement The motion of a human body through space can be precisely modeled as the motion of a particle at the body's center of mass. The components of the displacement of an athlete's center of mass from the beginning to the end of a certain jump are described by the two equations...

Homework Statement A girl throws her set of keys to her friend upward who is in a window 3.90m above. the keys are caught later at 1.30s by the friends hand. Homework Equations a. With what initial velocity were the keys thrown? b. What was the velocity of the keys just before they...

Finding a collision time... Homework Statement Sue, driving at 33 m/s enter a one lane tunnel. She then observes a slow moving van 175 m ahead traveling with velocity 5.40 m/s. Sue applies here brakes but can accelerate at only -2.00m/s^2. Homework Equations Determine how far into the...

Homework Statement A hare and tortoise compete in a race over a course of 3.70km long. The tortoise crawls straight and steadily at its max speed of .900m/s toward the finish line. The hare runs at its max speed of 1.00m/s toward the goal for .800 km and then stops to taunt the tortoise...

Homework Statement A person walks first at a constant speed of 47.0m/s along a straight line from point A to point B and then back along the line from B to A at a constant speed of 3.10m/s Homework Equations What is her average speed over the entire trip? The Attempt at a Solution...