question archive 1)Two balls are thrown reach the same height
1)Two balls are thrown reach the same height
Subject:PhysicsPrice: Bought3
1)Two balls are thrown reach the same height. Which of the following is definitely true? a) The x-components of the initial velocity are the same. b) The y-components of the initial velocity are the same. c) Both balls land at the same horizontal distance. d) The magnitudes of the initial velocity are the same.
2, 2. A rollercoaster of mass m starts from rest at height y1, however because the track was not properly greased only makes it to the height y2 before it comes to rest (there are safety brakes that keep the coaster from rolling backwards). The work done by friction = a) mg(y2 − y1) b) µKmg(y2 + y1) c) -mg(y2 − y1) d) -µKmg(y2 − y1) e) Not enough information to tell.
3,True or False. Conservative forces do not depend on path.
4, Vectors ~r1 = - 3.0 m ˆj and ~r2 = 3.0 m ˆi describe an object's position. Draw vector ?~r = ~r2 - ~r1 AND calculate the magnitude ?r and direction θ, of ?~r.
5, An object rotates initially at ω0=13.0 rotations per minute (rpm) and increases to ω=21.0 rpm in t=60 s. Calculate the angular acceleration of the object.
