26.1Q) Quiz: Retake: Free Fall and Projectile Motion

Ryan is running at a horizontal speed of 1.23 m/s.

While running, Ryan throws a  football straight up into the air with an initial speed of 30 m/s.

It is caught at the same distance above the ground that it was thrown from.

• 30 m/s

• Horizontal a

• 0 m/s²

• Vertical V₀

• Unknown

• Vertical V_f

• 0 m/s

• Horizontal T

  =
  Vertical T

• 1.23 m/s

• Horizontal V₀

  =

  Horizontal V_f

What equation should you use to answer the question:

"How long is it in the air?"

Answer explanation

Equations 1, 2 and 4 contain Y_f . Using them would leave us with one equation with two unknowns which we cannot solve.

Tags

NGSS.HS-PS2-1

What equation(s) can you use to answer the question:

How far does the ball move horizontally before Ryan catches it?

Answer explanation

Equations 1 and 2 contain both t and X_f. Either equation will work.

Answer explanation

Equations 1 and 2 contain both t and X_f. Either equation will work.

xf = 7.5276

David is running with a horizontal speed of 2 m/s.

While running, David tosses a ball into the air at 10 m/s.

It is caught at the same distance above the ground that it was thrown from.

• 10 m/s

• Horizontal T

  =
  Vertical T

• 0 m/s²

• Vertical V₀

• Unknown

• Horizontal V₀

  =

  Horizontal V_f

• 2 m/s

• Vertical V_f

• 0 m/s

• Horizontal a

Tags

NGSS.HS-PS2-2

What equation should you use to answer the question:

"How high does the ball go?"

Answer explanation

Using equation 1, 2, or 3 will result in two unknowns (V_f and t). This cannot be solved. We must use Equation 4 because it only have one unknown (V_f).

Tags

NGSS.HS-PS2-1

What equation(s) can you use to answer the question:

"How long does the ball stay in the air?

Answer explanation

Equation 1, 2, and 3 have time in them.

Answer explanation

t= 1.02 s