Question

A dummy is fired vertically upward from a canon with a speed of 40 m/s. How long is the dummy in the air? What is the dummies maximum height?

Answer 1

KINEMATICS

Uniform or constant motion in a straight line (rectilinear). Speed or velocity constant and/or acceleration constant. If motion is up and down and/or has an up and down component then acceleration omn earth will be g. g is about 10m/s/s.

speed = distance/time

velocity = displacement/time

s=distance ... u=initial speed ... v = final speed ... a = acceleration ... t = time

v=u+at

v^2=u^2+2as

s=ut+1/2at^2

Answer 2

8,1549 seconds

81,5494 meters is the maximum height

Step-by-step explanation:

REmemeber that in physiscs the formula for maximum height is given by the next representation:

`H=(Vo^2)/(g)`

Sow we just have to insert the values into the formula:

`H=(Vo^2)/(2g)\\H=(40^2)/(2*9,8)\\h=(1600)/(19,62)\\h=81.5494meters`

Now the time that it takes the dumy to fall from that height is given by thenext formula, and then we just multiply that by 2 to calculate the time that the dummy was in the air:

`t=\sqrt{(2d)/(g) } \\`

Now we insert the data we have into the formula:

`t=\sqrt{(2d)/(g) } \\ t=\sqrt{(2(81,5494))/(9,8) }\\t=\sqrt{(16309)/(9,81) } \\\\t=4,077s`

in free fall the amount of time it takes an object going up is the same amount of time it take to fall, so we just multiply the time falling by 2 and we get taht the dummy was in the air for 8.1549 seconds.