Question #21594

2 Answers
Jun 14, 2017

When there is no air resistance, at maximum height all initial kinetic energy is converted to its potential energy. Mathematically
1/2mv^2=mgh_max
=>h_max=v^2/(2g)
Inserting given values and taking g=9.81ms^-2 we get
h_max=28^2/(2xx9.81)
h_max=39.96m, rounded to two decimal places.

Jun 14, 2017

40m

Explanation:

At max. height the vertical velocity is 0 (assume it is the final)

We can use the equation (v_f)^2=(v_i)^2-2ad

In this case a is the acceleration due to gravity (9.8)

Solve for d (the height)

d=((v_f)^2-(v_i)^2)/(-2a)

color(white)d=(0-28^2)/((-2)(9.8))

color(white)d=40m