Question

Y = 12 + 4.5t

A moving object begins to accelerate along a track. When the object has been accelgrating along the track for t seconds, the object is moving at v meters per second, as shown in the equation above. What is t when v is 84 ?
A) 42
B) 16
C) 84
D) 147

Answer 1

To find the time t when the velocity v is 84 meters per second, solve the equation y = 12 + 4.5t. The solution is t = 16 seconds, which corresponds to option B).

Step-by-step explanation:

The equation y = 12 + 4.5t represents the velocity of the object as a function of time. In this equation, y represents the velocity in meters per second and t represents the time in seconds. To find t when v is 84 m/s, we can set y equal to 84 and solve for t: 84 = 12 + 4.5t. Subtracting 12 from both sides: 72 = 4.5t. Dividing both sides by 4.5: t = 16. Therefore, when the object is moving at 84 m/s, t is 16 seconds.