A car is traveling at a speed of 15m/s. It experiences an acceleration of -3m/s^2, that lasts for 4 seconds. What is the final velocity of the car?

27m/s

Explanation:

u=15m/s

a=3m/s^2

t=4s

v=u+at

v=15+3(4)

v=27m/s

c)as speed changes, wavelength and frequency change.

everything changes!

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.