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 15 m/s. If the brick is in flight for 3.0 s, how tall is the building?
Who are the experts?Our certified Educators are real professors, teachers, and scholars who use their academic expertise to tackle your toughest questions. Educators go through a rigorous application process, and every answer they submit is reviewed by our in-house editorial team.

You are watching: A brick is thrown upward from the top of a building at an angle of Let us project the position of the brick to the vertical axis. Denote the initial height by H (it is the height of the building) and obtain the following equation:

H(t) = H + V0*sin(a)*t - (g*t^2)/2.

Here V0 is the initial velocity (15m/s), a is an angle above horizontal...

Start your 48-hour free trial to unlock this answer and thousands more. Enjoy les-grizzlys-catalans.org ad-free and cancel anytime.

Let us project the position of the brick to the vertical axis. Denote the initial height by H (it is the height of the building) and obtain the following equation:

H(t) = H + V0*sin(a)*t - (g*t^2)/2.

Here V0 is the initial velocity (15m/s), a is an angle above horizontal (25°) (+ is from the "upward"). And g is the acceleration of gravity (approx. 9.8m/s^2).

We know that H(3s)=0, so

H = g*(3^2)/2 - V0*sin(a)*3 = 9.8*4.5 - 15*sin(25°)*3.

Use calculator and obtain the answer, 44.1-19=25.1(m).

Of course we neglect the air resistance here.

See more: What Is Acting In Anticipation Of Future Problems Is:, Habit #1 I Am The Force

Approved by les-grizzlys-catalans.org Editorial Team

Submit Question

See every

## Related Questions

Browse All
Math

Latest answer posted September 22, 2011 at 2:14:37 PM

A ball is thrown horizontally from the top of a building 49.5 m high. The ball strikes the ground at a point 43.5 m from the base of the building.Find the initial velocity of the ball. The...

Math

Latest answer posted October 04, 2009 at 11:25:10 PM

At what speed must the second ball be thrown so that it reaches the same height as the one thrown vertically? Answer in units of m/s.A ball is thrown straight upward and returns to the throwers...

Math

Latest answer posted November 07, 2011 at 2:23:26 AM

A surveillance camera is mounted on the top of an 80 m tall building. The angle of elevation from the camera to the top of another building is 42 degree. The angle of depression from the camera to...

Math

Latest answer posted May 11, 2012 at 2:20:51 AM

A ladder 20 feet long leans against a vertical building. If the bottom of the ladder slides away from the building horizontally at a rate of 3 feet/sec.how fast is the ladder sliding down the...

Math

Latest answer posted September 13, 2012 at 2:55:51 PM

An object is thrown straight up from ground level with a speed of 50 m/s. If g = 10 m.s^2, what is its distance above ground level 1.0 s later.