What, precisely, does vi represent in that equation?md3v said:(vf)^2 = (vi)^2 + 2a(x)
(0) = (vi)^2 + 2(-9.8)(10)
Be careful here. The height of the bar which the football clears is measured in feet. The distance the ball starts from the goal is measured in yards. You have g measured in m/s2. Pick a unit system and put everything in consistent units. BTW, 9.8 m/s2 ≈ 32.2 ft/s2md3v said:Homework Statement
A football started on the ground 64 yards from the base of the goal post and barely clears the 10 ft high bar. The initial trajectory of the football was 43 deg above the horizontal. What was its initial speed?
Homework Equations
The Attempt at a Solution
(vf)^2 = (vi)^2 + 2a(x)
(0) = (vi)^2 + 2(-9.8)(10)
Initial velocity, denoted as v0, is the initial velocity of an object at the start of a motion. It is the velocity at which the object starts moving and is typically measured in meters per second (m/s).
Initial velocity can be calculated using the formula v0 = (v - at), where v is the final velocity, a is the acceleration, and t is the time elapsed. Alternatively, it can also be calculated using the formula v0 = Δx / t, where Δx is the displacement and t is the time elapsed.
As mentioned before, initial velocity is the velocity at the start of a motion, while final velocity is the velocity at the end of a motion. Initial velocity is denoted as v0, while final velocity is denoted as v. Both are measured in meters per second (m/s).
Knowing the initial velocity of an object is important in understanding its motion and predicting its future position. It is a crucial component in many equations used to solve problems related to motion, such as calculating the displacement, acceleration, and time elapsed.
You can use the formula v0 = (v - at) to find the initial velocity, where v is the final velocity, a is the acceleration, and t is the time elapsed. Alternatively, you can also use the formula v0 = Δx / t, where Δx is the displacement and t is the time elapsed. Both of these formulas require the knowledge of at least one other variable, such as time or displacement.