What height will a dart achieve 7 seconds after being blown straight up at 50 m/s?

1 Answer
Darshan Senthil
Oct 12, 2014

It is 100 m

Since this is motion in only one dimension, it is a relatively simple problem to solve.

As we're given time, acceleration and initial velocity, we can use our time dependent equation of kinematics, which is:

Deltay=v_ot+1/2at^2

Now let's list out our given values:

t = 7 seconds
v_o = 50m/s
a = -9.8m/s^2 (Gravity acting downwards)

So now all we need to do is plug in and solve:

Deltay = 50(7) + 1/2(-9.8)(7^2)

Deltay =109.9 m#

However, we would round this down to 100 because of the 1 significant digit in our given information (if you have 50. and 7.0, you would round it to 2 sig figs, which would be 110).

Hope that helped :)

Related questions
See all questions in Falling Objects
Impact of this question
6160 views around the world
You can reuse this answer
Creative Commons License