A brick is dropped (zero initial speed) from the roof of a building. The brick strikes the ground in 1.90 s. You may ignore air resistance, so the brick is in free fall. (a) How tall, in meters, is the building?

Video transcript

Hello. So in this problem the ball is dropped from the top of the cliff. The ball hits the ground at 3.8 seconds. Which resistance is neglected. So the ball is in free fall under rally. What is the height of the cliff? So it is dropped from this clip with some initial velocity which is zero. In this case We know that it hits the ground in 3.8 It is free fall. The acceleration is just the acceleration due to gravity which is 9.81. It's the Second Square. We want to find the distance where the height of the cliff To recall the kinetic equations which is the FBI. 80 2nd the obscurity of the iceberg. Those 2 8 delta ivs dr X. Is equal to B. I. T. Was 1/2 a teaspoon. So given these values of knowns and unknowns, you can see that equation three pretty much has everything that we need. We're looking for the distance delta X. Delta age. In this case B. I. Is simply zero. So this B. I. T. Terms cancel. We have A. And T. So we can use equation for you to solve this problem. This case delta H. Is equal to B. I. T. I just want to have a G. In this case we know that the eye of zero. So these two cancers get the delta H. Is just one half. So we can make these substitutions. Want to have. I'm saying I'm 21 second squared Times 3.80 seconds. I swear age is equal to 70.7 m, which is the distance it travels for the height of the club, 70. answer choices of the subject of a great deal.