Gabrielle just finished building a slingshot as a summer project. To test it, she launches a rock upward. The rock's height above the ground in meters can be modeled by the expression 1.5+22t−4.9t2, where t is the time in seconds after the rock is launched.What does the number 1.5 represent in the expression?(A)the height in meters of the rock when it reaches its highest point(B)the time in seconds from when the rock is launched until it reaches its highest point(C)the height in meters of the rock when it is launched(D)the time in seconds from when the rock is launched until it hits the ground
Q. Gabrielle just finished building a slingshot as a summer project. To test it, she launches a rock upward. The rock's height above the ground in meters can be modeled by the expression 1.5+22t−4.9t2, where t is the time in seconds after the rock is launched.What does the number 1.5 represent in the expression?(A)the height in meters of the rock when it reaches its highest point(B)the time in seconds from when the rock is launched until it reaches its highest point(C)the height in meters of the rock when it is launched(D)the time in seconds from when the rock is launched until it hits the ground
Expression for rock's height: The expression for the rock's height is 1.5+22t−4.9t2. The term 1.5 is a constant, which means it's the value of the height when t=0.
Confirming initial height: To confirm, let's plug t=0 into the expression: 1.5+22(0)−4.9(0)2=1.5.
Units of measurement: Since the height is measured in meters and t is the time in seconds after launch, the number 1.5 must represent the initial height of the rock when it is launched.
More problems from Interpret parts of quadratic expressions: word problems