# intro to physics

a toy rocket moving vertically upward passes by a 2.2m- high window whose sill is 7.0m above the ground. the rocket takes 0.17s to travel the 2.2m height of the wondow
part a): what was the launch speed of the rocket ? assume the propellant is burned very quickly at blastoff

part b) how high will the rocket go ?

1. 👍 0
2. 👎 0
3. 👁 1,408
1. Let’s find the initial velocity of rocket.
Since
h(o) = v(o)•t - g•t^2/2,
v(o) = 2• h(o) /t +gt/2 = 22.2/0.17 + 9.8•0.17/2 = 25.047 m/s.
Now let’s find the time of reaching the max height
0 = v(o) - g•t1
t1 = v(o)/g = 25.047/9.8 = 2.56 s.
The max height (from the sill)
h1 = v(o)•t1-gt1^2/2 = 25.047•2.56 =9.8•(2.56)^2/2 = 96.13 m.
The max height (from the ground) is
H = 96.13 + 7 = 103.13 m.
H = gt2^2/2 .
t2= sqrt(2•H/g) = sqrt(2•103.13/9.8) = 4.59 s.
v =g•t2 = 9.8•4.59 = 44.96 m/s

1. 👍 0
2. 👎 2
2. where did that 22.2 come from?

1. 👍 0
2. 👎 0
3. v(o) = 2• h(o) /t +gt/2 = 2.2/0.17 + 9.8•0.17/2 = 25.047 m/s.

1. 👍 0
2. 👎 0
4. 22.2 was a typo error of 2*2.2, but the result was ok.

1. 👍 0
2. 👎 0
5. thats wrong, no 2* h(o)

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Algebra

A toy rocket that is shot in the air with an upward velocity of 48 feet per second can be modeled by the function f(t)=-16t^2+48t , where t is the time in seconds since the rocket was shot and f(t) is the rocket’s height. What

2. ### physics

A small weather rocket weighs 14.7 N. The rocket is carried up by a balloon. The rocket is released from the balloon and fired, and its engine exerts an upward force of 10.2 N on the rocket. What is the acceleration of the rocket?

3. ### pre ap math

a toy rocket is launched from a platform that is 48 feet high. the rockets height above the ground is modeled by h=-16t^2+32t+43. find the maximum height of the rocket find the time it will take for the rocket to reach the ground.

4. ### physics

A catapult launches a test rocket vertically upward from a well, giving the rocket an initial speed of 79.0 m/s at ground level. The engines then fire, and the rocket accelerates upward at 3.90 m/s2 until it reaches an altitude of

.A toy rocket is shot vertically into the air from a launching pad 5 feel above the ground with an initial velocity of 72 feet per second. The height h, in feet, of the rocket above the ground as t seconds after launch is given by

2. ### physics

a brick is dropped form the roof of a building. On the way down it passes a 2m high window and is observed to pass from the top to the bottom of the window in 0.25s. (a) How fast was it moving when it passed the top of the window?

3. ### physics

A toy rocket, launched from the ground, rises vertically with an acceleration of 32 m/s^2 for 4.1 s until its motor stops. Disregarding any air resistance, what maximum height above the ground will the rocket achieve? The

4. ### Physics

A ball is thrown vertically upward from a window with an initial velocity of 10m/s. if it hits the ground below the window 5.0s later, what is the height of the window...can you tell me the steps on how to do this please...

1. ### math

A toy rocket is launched straight up into the air with an initial velocity of 60 ft/s from a table 3 ft above the ground. If acceleration due to gravity is –16 ft/s2, approximately how many seconds after the launch will the toy

2. ### Physics

A window is 1.50m high. A stone falling from above passes the top of the window with a speed of 3m/s. When will it pass the bottom of the window?

3. ### Physics

A test rocket is launched vertically from ground level (y=0m), at time t=0.0 s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen to 97 m and

4. ### Physics

If toy rocket rises vertically and then falls back to the ground, what changes occur in the rocket's velocity and acceleration. Please give a sentence explanation not a formula