The problem involves a rock being thrown straight down from a height of 70 m with an initial velocity of 10.5 m/s. Participants are tasked with calculating the displacement and velocity of the rock after 1.0 second, considering upward as the positive direction.
Some participants have provided calculations for displacement and engaged in clarifying the concept of acceleration. There is an ongoing exploration of how to derive the velocity from the given information, with no explicit consensus reached yet.
Participants are working within the constraints of the problem statement and the definitions provided, with a focus on understanding the relationships between displacement, velocity, and acceleration.
Lana Elcic said:Homework Statement
A rock is thrown straight down with an initial velocity of 10.5 m/s from the Verrazano Narrows Bridge in New York City. The roadway of this bridge is 70 m above water. Take upwards to be the positive direction.
Calculate the displacement and velocity at a time of 1.0 s.
The attempt at a solution
-5.6
C. Lee said:So what is your question?
Can you give some more details on how you ended up with that answer?
Lana Elcic said:I've figured out the displacement by (10.5)(1)+(1/2)(9.8)(1.0)^2=-15.4
I don't know how to find velocity though.
C. Lee said:Alright.
So, you have used the gravitational acceleration 9.8m/s^2 to calculate the displacement.
What is the definition of acceleration?
Right. So the acceleration is constant, and you are given with initial velocity. You can now calculate the velocity at t = 1.0 s.Lana Elcic said:rate of change of velocity
C. Lee said:Right. So the acceleration is constant, and you are given with initial velocity. You can now calculate the velocity at t = 1.0 s.