You throw a ball straight up with an initial velocity of 15.0 m/s. It passes a tree branch on the way up at a height of 7.00 m. How much additional time will pass before the ball passes the tree branch on the way back down?

# Tag: Science

Semi-trailer trucks have an odometer on one hub of a trailer wheel. The hub is weighted so that it does not rotate, but it contains gears to count the number of wheel revolutions—it then calculates the distance traveled. If the wheel has a 1.15 m diameter and goes through 200,000 rotations, how many kilometers should the odometer read?

A physics major is cooking breakfast when he notices that the frictional force between his steel spatula and his Teflon frying pan is only 0.200 N. Knowing the coefficient of kinetic friction between the two materials, he quickly calculates the normal force. What is it?

A 63.0-kg sprinter starts a race with an acceleration of 4.20 m/s^2 . What is the net external force on him?

Freight trains can produce only relatively small accelerations and decelerations. (a) What is the final velocity of a freight train that accelerates at a rate of $latex 0.0500\:m/s^2&s=1&fg=000000$ for 8.00 minutes, starting with an initial velocity of 4.00 m/s? (b) If the train can slow down at a rate of $latex 0.550\:m/s&s=1&fg=000000$, how long will it take to … Continue reading College Physics Problem 2.29

What are the important points when dealing with scalars and vectors? I have summarized down below some four important concepts you need to know when solving problems involving scalars and vectors. A scalar can be a negative or positive number. Scalar has magnitude but without direction. A vector is a quantity that has a magnitude, … Continue reading Scalars and Vectors