physic

A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 15 m/s. If the brick is in flight for 2.7 s, how tall is the building? in (m)

  1. 👍 0
  2. 👎 0
  3. 👁 129
asked by mark
  1. Vo = 15m/s[35o].
    Yo = 15*sin35 = 8.60 m/s.

    Y = Yo + g*Tr = 0, Tr = -Yo/g = -8.60/-9.8 = 0.88 s. = Rise time.

    h1 = Yo*Tr + 0.5g*Tr^2.
    h1 = 8.60*0.88 - 4.9*0.88^2 = 3.77 m. Above top of bldg.

    Tr+Tf = 2.7, Tf = 2.7-Tr = 2.7-0.88 = 1.82 s. = Fall time from max ht. to gnd.

    h2 = 0.5g*Tf^2 = 4.9*1.82^2 = 16.2 m. Above gnd.

    Hb = h2-h1 = 16.2 - 3.77 = 12.5 m = Height of the bldg.

    Tr+Tf = 2.7, Tf = 2.7-Tr =

    1. 👍 0
    2. 👎 0
    posted by Henry
  2. Oops! Disregard last line of this post.

    1. 👍 0
    2. 👎 0
    posted by Henry

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    A brick is thrown upward from the top of a building at an angle of 10° to the horizontal and with an initial speed of 11 m/s. If the brick is in flight for 2.8 s, how tall is the building?

    asked by mel on February 9, 2010
  2. physics

    A brick is thrown upward from the top of a building at an angle of 25° to the horizontal and with an initial speed of 17 m/s. If the brick is in flight for 2.5 s, how tall is the building?

    asked by tiffany on September 20, 2010
  3. physics

    A brick is thrown upward from the top of a building at an angle of 25° to the horizontal and with an initial speed of 16 m/s. If the brick is in flight for 3.1 s, how tall is the building?

    asked by sid on February 21, 2012
  4. physics help please

    A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 15 m/s. If the brick is in flight for 2.7 s, how tall is the building? in (m)

    asked by lisa on February 4, 2016
  5. physics

    A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 15 m/s. If the brick is in flight for 2.7 s, how tall is the building?

    asked by lisa on February 5, 2016
  6. physics

    A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 15 m/s. If the brick is in flight for 2.7 s, how tall is the building? (in m) could someone help me please!!!

    asked by lisa on February 7, 2016
  7. physics

    A brick is thrown upward from the top of a building at an angle of 40° to the horizontal and with an initial speed of 16 m/s. If the brick is in flight for 3.4 s, how tall is the building?

    asked by kaf on January 29, 2012
  8. physics

    A brick is thrown upward from the top of a building at an angle of 40° to the horizontal and with an initial speed of 12 m/s. If the brick is in flight for 2.5 s, how tall is the building?

    asked by Anonymous on September 25, 2010
  9. physics

    A brick is thrown upward from the top of a building at an angle of 15° to the horizontal and with an initial speed of 16 m/s. If the brick is in flight for 2.8 s, how tall is the building?

    asked by Claudia on September 27, 2010
  10. physics

    A brick is thrown upward from the top of a building at an angle of 35° to the horizontal and with an initial speed of 14 m/s. If the brick is in flight for 3s, how tall is the building?

    asked by TNT on February 16, 2018

More Similar Questions