8. A projectile launched horizontally with a speed of 10.0 m/s hits the ground in 1.2 seconds. If the projectile had been launched at 20 m/s in the same direction, it would have hit the ground in
a. 0.6 seconds
b. 1.2 seconds
c. (2.4 seconds
d. 4.8 seconds

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error

(**i would really appreciate if this was answered soon** ) which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Would it be correct to say the doppler effect is the apparent change in the speed of a wave due to the motion of the source? be sure to fully explain your position using at least 3 complete content related sentences.