A rock is thrown straight down from the Verrazano Narrows Bridge with an initial velocity of 10.5 m/s. After 1.0 second, the displacement is calculated to be -15.4 meters using the formula (initial velocity * time) + (1/2 * gravitational acceleration * time^2), where gravitational acceleration is 9.8 m/s². The velocity at this time can be determined using the formula: final velocity = initial velocity + (acceleration * time). This discussion emphasizes the application of kinematic equations in solving problems related to falling objects.
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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.