Question

A stone is tossed straight up into the air In a coordinate system where going down is positive. a) What is the initial velocity of the stone? Is it zero, positive or negative? b) Show that acceleration due to gravity is positive regardless whether the stone is on it's way up or on its way down after turning around at the maximum height. c) Argue that at maximum height, the acceleration is not zero. though the velocity is zero. d) What is the velocity when the stone hits the ground? Is it zero, positive, or negative? faster or slower than the initial velocity of the stone? e) Suggest a way to measure g based on one or more relevant kinematic equations.

Answer 1

a)As the stone is tossed up the direction of movement is upwards so , the velocity will be negative

b) the force of gravity by. Earth is always towards the earth thus , the acceleration due to gravity is always positive

c) at maximum height the velocity will be zero since if the there was some velocity still left it Will go even more up but as argued in b) the force of gravity is constant thus acceleration will be constant

d) when it is reaching the ground it is travelling in downward direction, thus it is positive velocity

E) if we know the height and calculated the time in which it comes back we can use the formula

t = 2sqrt(2h/g)