A train is at rest at a station. The train then moves away from the station and after 20 seconds it's velocity is 15m/s and moves at this velocity for 60 seconds. it's velocity increases to 20m/s over 5 seconds. it moves at a velocity of 20m/s for 120 seconds and then slows down to come to a stop after a further 30 seconds. during which period was the acceleration of the train the highest?

A500g object falls off a cliff and losers 100 j from its gravitational potential energy store. if the gravitational field strength g=9.8n/kg, how high is the cliff?

Which of these questions might a character ask if the conflict is man versus self? a. which path should i take to better myself? b. which boulder will be too heavy for me to carry? c. which friend is going to ditch me today? d. all of the above

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?