An accelerating object has an initial speed of u=(12.4 +-0.1)^-1and a final speed of v=(28.8 +-0.2)ms-1. The time interval for this change in speed is t=(4.2 +-0.1)s. Acceleration is defined as a=(v-u)/t. Calculate the acceleration and its uncertainty.

Why is alternating current more effective at long–distance travel than direct current? a. the power lines are made out of conductors. b. transformers increase or decrease voltage as needed. c. the ac generator is more efficient. d. ac has lower voltage than dc.

Rank the automobiles based on the magnitude of the force needed to stop them, from largest to smallest.2000 kg car going 5m/s500 kg car going 20 m/s1000 kg car going20m/s500 kg car going10m/s1000 kg car going10/s4000 kg car going 5m/s 0 0 603

Two waves maximally constructively interfere at a point in space. among the options below, select the possible value of their phase difference at that point in space.a. zerob. πc. π/2d. not determinable by the information provided