Lisa is standing on a dock beside a lake. She drops a rock from her hand into the lake. After the rock hits the surface of the lake, the rock's distance from the lake's surface changes at a rate of −3 inches per second. If Lisa holds her hand 5 feet above the lake's surface, how far from Lisa's hand is the rock 5 seconds after it hits the surface?

If the rock is going down at 3 inches per second, then to find how far beneath the surface of the lake the rock was after 5 seconds, just multiply 3*5.
After 5 seconds, the rock is at -15 feet.
To find how far away from Lisa's hand the rock is, we need to add 5 because her hand is 5 feet above the lake's surface.
After 5 seconds, the rock is 20 feet away from Lisa's hand.

Answered by corajune99 | 2024-06-10

After 5 seconds, the rock is 20 feet away from Lisa's hand. ;

Answered by Celeste1100 | 2024-06-13

After dropping the rock, it sinks at a rate of -3 inches per second. After 5 seconds, the rock is 15 inches below the lake surface, making it 75 inches, or 6.25 feet, away from Lisa's hand. Therefore, the distance from her hand is 75 inches.
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Answered by corajune99 | 2024-09-27