The position of a particule is moving along the x-axis is given by x=7.8 + 9.2t - 2.1t³ where x in meter and t in second
a)what is the velocity at t=3.5
b)is the velocity constant or continuous?
c)what is the displacement of the particle after 3 seconds

we need to know the time interval during which the force acts. impulse of force = momentum change

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.