The position of the mass is given by (in cm):

The velocity is the derivative of the position:

Substituting t=0.40 s, we can find the velocity at this time:
Answer:
1/f = 1/i + 1/o thin lens equation
1/i = 1/f - 1/o
i = o * f / ( o - f) = 50 * (-20) / (50 - (-20)) = -14.3 cm
The final image is erect and 14.3 cm behind the curved surface
M = -o / i = 14.3 / 50 = .29 magnificaton of object
S = .29 * 25 cm = 7.1 cm appearance of bird in mirror (height)
B green house gases is the correct problem
T = 2*pi*Sqrt (L/g)
T = Period = Time to complete one oscillation, L = Length of the pendulum, g = gravitational acceleration.
Then,
L = {T/(2*pi)}^2*g = {7/(2*pi)}^2*3.711 = 4.606 m
E = 0.25 = m*g*h
<span>h = 0.25/(m*g) = 0.25/(0.125*10) = 0.25/1.25 = 1/5 = 0.20 m
I hope this helps you have a great day and im sorry it took so long to get an answer</span>