Question

Martha was leaning out of the window on the second floor of her house and speaking to Steve. Suddenly, her glasses slipped from her nose. The glasses hit the ground in 2.2 seconds. Neglecting the effects of air resistance, answer the questions below. A. What is the height of the window from the ground? B. What was the impact velocity of the glasses?

Answer 1

A. d ≈ 23.72 m.

B. v ≈ 21.56 m/s.

Step-by-step explanation:

d = height

v = final velocity

v0 = Initial velocity

g = gravity

t = time

A.

Given that the time is 2.2 seconds and the initial velocity is 0, we can replace the values in to the formula.

d = v0 * t + 0.5 * g * t^2

d = 0 * 2.2 + 0.5 * 9.8 * 2.2^2

d = 0 + 23.716

d ≈ 23.72 m.

B.

​

​Sincec the initial speed is 0 m/s,

v^2 = 2 * g * d

v = sqrt(2 * g * d)

v = sqrt(2 * 9.8 * 23.72)

v = sqrt(464.912)

v ≈ 21.56 m/s

Answer 2

s = 23.72 m

v = 21.56 m/s²

Step-by-step explanation:

given

time to reach the ground (t) = 2.2 second

we know that

a) s = u t + 0.5 g t²

u = 0 m/s

g = 9.8 m/s²

s = 0 + 0.5 × 9.8 × 2.2²

s = 23.72 m

b) impact velocity

v = √(2gh)

v = √(2× 9.8 × 23.72)

v = √464.912

v = 21.56 m/s²