Aspace shuttle is approaching the surface of the moon to land. it approaches the moons surface with an initial velocity of 28m/s and is slowing at a rate of -2m/s^2. show all work and units for problems. a) draw velocity vs time graph
b) when will shuttles velocity equal zero?
c) how far above the surface of the moon was the shuttle when it began to slow down?

Explanation:

a ) Velocity vs time graph will be a straight line with negative slope , making a slope of 2 because slope of v-t graph gives the value of acceleration.

b ) v = 0 , u = 28 m/s

t = ?

v = u - at

0 = 28 - 2 t

t = 14 s

shuttle velocity will become zero after 14 sec.

c ) v ² = u² - 2 a s

0 = 28² - 2 x 2 x s

s = 28² / 4

= 196 m .

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.