Question

multiple choice 5 points the bottom of a garage door is 2.8 meters above the ground. when a button is pushed, the door moves down at a rate of 0.6 meter per second. which equation can be solved to find t, the time in seconds it takes the door to close completely? 2.8 - 0.6t = 0 0.6 + 2.8t = 0 0.6 - 2.8t = 0 2.8 + 0.6t = 0 clear my selection

Explanation:

Step1: Analyze the problem

The garage door starts at a height of 2.8 meters and moves down at a rate of 0.6 meters per second. We need to find the time \( t \) when the height is 0 (completely closed). The height \( h \) as a function of time \( t \) should be the initial height minus the distance moved down, which is \( 2.8 - 0.6t \). We set \( h = 0 \) to find when it's closed, so the equation is \( 2.8 - 0.6t = 0 \).

Step2: Evaluate the options

• Option 1: \( 2.8 - 0.6t = 0 \) matches our derived equation.
• Option 2: \( 0.6 + 2.8t = 0 \) has incorrect terms (initial height is 2.8, rate is 0.6, and the operation should be subtraction for the distance moved down).
• Option 3: \( 0.6 - 2.8t = 0 \) has reversed coefficients and incorrect operation.
• Option 4: \( 2.8 + 0.6t = 0 \) would imply the door is moving up (adding height), which is wrong.

Answer:

A. \( 2.8 - 0.6t = 0 \)