Over a time interval of 1.52 years, the velocity of a planet orbiting a distant star reverses direction, changing from +20.5 km/s to -15.8 km/s. Find (a) the total change in the planet's velocity (in m/s) and (b) its average acceleration (in m/s²) during this interval. Include the correct algebraic sign with your answers to convey the directions of the velocity and the acceleration. (a) Number i (b) Number i Units Units

A particle moves so that its position (in meters) as a function of time (in seconds) is r = î + 5t2 j + 5t k. (Use the following as necessary: t.) (a) Write an expression for its velocity as a function of time. V = m/s (b) Write an expression for its acceleration as a function of time. a = m/s?

A car is traveling with a constant speed along a road that has a form of a square. The car starts at the beginning of one side of the square and covers two and a half sides. The speed of the car is 50 miles / hour. What is its average velocity? Please provide step by step & clear solution!

Cities A and B are connected by a straight road of total length 200 miles.Two cars depart cities A and B at the same time, moving towards each other. The A-car travels at 60 miles per hour, and the B-car at 40 mph. At the same time, a fly starts off from the front bumper of the A-car flying at 100 mph. It flies towards city B until it touches the bumper of the B-car, and then flies back, touches the A-car, flies back, etc, until the cars collide and the fly is squashed. The standard trick question is - what is the total distance traveled by the fly? At first sight one would think that the problem should be solved by the series summation, but that’s not necessary - the cars meet after 2 hours, and during that time the fly traveling at 100 mph covers exactly 200 miles. Now that you know the answer, solve this problem using the series summation [1].