# math

The time t (in seconds) that it takes for an object to fall a distance of s feet is given by the formula

t = radical symbol s /4

In some places, the Grand Canyon is one mile (5,280 feet) deep. How long would it take a stone dropped over the edge of the canyon to hit bottom?

18 or 26 seconds?

1. 👍
2. 👎
3. 👁
1. I get neither of those. Put this into the google search window:

sqrt(5280/4)

Finally, your formula is not accurate.

1. 👍
2. 👎
👤
bobpursley
2. ok i got

36.3318042

thank you

1. 👍
2. 👎
3. would the formula be

t = sqrt of 5280/4?

1. 👍
2. 👎
4. for a sense check - check in SI units!

1 mile is approx 1600 metres, a is approx 10 m s^-2

t=sqrt(2s/a)

t = sqrt(2 x 1600/10)

t= sqrt(320)

t is approx 18 (8x sqrt5)

or have I made a mistake?

1. 👍
2. 👎
5. Jennifer
I answered this same question for you yesterday.

http://www.jiskha.com/display.cgi?id=1224095175

1. 👍
2. 👎
6. d = (1/2)g t^2
in feet, seconds units g = 32 ft/s^2 approximately
so
d = 16 t^2
t^2 = d/16
t = (1/4)(sqrt d)
if d = 5280
t = .25 (sqrt 5280)
= .25 * 72.7
=18.2 seconds

1. 👍
2. 👎

## Similar Questions

1. ### Gravity Unit Test

1) Which phrase defines gravitational force? (1 point) a. the force pulling objects down to Earth's surface b. an attractive force between two objects due to their masses c. a repulsive force between two objects due to their

2. ### calculus help check and help

if an object with mass m is dropped from rest, one model for its speed v after t seconds, taking air resistance into account is v= mg/c(1-e^(-ct/m)) where g is the acceleration due to gravity and c is a positive constant

3. ### science HELP PLZZZZZZ

1 Q On which object will earths gravity act with the greatest magnitude A. A toaster B. A television C. A piano D. A banana 2 Q Why does a beach ball weigh less than a bowling ball? A. The beach ball has more air. B. The beach

4. ### Math

An object's velocity after t seconds is v(t)= 38-2t feet per second. a. How many seconds does it take for the object to come to a stop (velocity = 0)? b. How far does the car travel during that time? c. How many seconds does it

1. ### math

Hi, Would you please check to see if I did this problem correctly? Your distance from lightning varies directly with the time it takes you to hear thunder. If you hear thunder 10 seconds after you see the lightning, you are about

2. ### math

The diagram below shows the speed time graph for a train travelling between two stations. The train starts from rest and accelerates uniformly for 150 seconds. It then travels at a constant speed for 300 seconds and finally

3. ### Math Help

Let v(t)=t^2−3t be the velocity, in feet per second, of an object at time t , in seconds. (c) What is the meaning of the quantity v(4)? Select all that apply if more than one statement is correct. A. In how many seconds will the

4. ### physics

The acceleration due to gravity on planet X is one fifth that on the surface of the earth. If it takes 3.5 s for an object to fall a certain distance from rest on earth, how long would it take to fall the same distance on planet

1. ### Physics

An object is released from rest at height h above the surface of the Earth, where h is much smaller than the radius of the Earth. It takes t seconds to fall to the ground. At what height should this object be released from rest in

2. ### MATH

The time (t, in seconds) for a free-falling object to fall d feet is described by the mathematical formula: t=d over the square root of 16 If a worker accidentally drops a hammer from a building and it hit the ground 4 seconds

3. ### Physics

Calculate the vertical distance an object dropped from rest covers in 12 seconds of free fall. (The unit of measure for distance is the meter, written as m.)

4. ### Physics

3. Consider a freely falling object. a. What is the acceleration (in m/s2) after 5 seconds of fall? b. What is the acceleration (in m/s2) after 10 seconds of fall? c. What is the velocity (in m/s) after 5 seconds of fall? d. What