A 10kg roller coaster does a loop-de-loop and it’s your job to make sure it is safe. The people will fall out if the cart’s speed is less than 40m/s when it goes upside down. How high up does the car have to be at point A to make it? Fill in everything else as well. Location

PE

KE

TE

A

h =

v = 0m/s

B

h = 0m

v =

C

h = 15m

PE=m*g*h

v = 40m/s

KE=0.5*m*v2=

TE=PE+KE

D

h = 0m

v =

E

h = 10m

v =

F

h = 20m

v =

•• al and bert are jogging side-by-side on a trail in the woods at a speed of 0.75 m/s. suddenly al sees the end of the trail 35 m ahead and decides to speed up to reach it. he accelerates at a constant rate of 0.50 m/s2, while bert continues on at a constant speed. (a) how long does it take al to reach the end of the trail? (b) once he reaches the end of the trail, he immediately turns around and heads back along the trail with a constant speed of 0.85 m/s. how long does it take him to meet up with bert? (c) how far are they from the end of the trail when they meet?

An equinox occurs when a. neither end of earth's axis is tilted toward or away from the sun. b. the north end of earth's axis is tilted away from the sun. c. the north end of earth's axis is tilted toward the sun. d. earth's axis is parallel to the sun's rays. select the best answer from the choices provided a b c d

Exercise 2. find the wavelength of a photon emitted when an electron jumps from the n = 3 energy level down to the n = 2 energy level. where is this photon in the electromagnetic spectrum?