A ladder of length l=12 m and mass m=45 kg lean against a wall (no friction between the wall and the ladder). The ladders upper end is at height h= 9.3 m above the pavement and which the lower end is supported (the pavement is not frictionless). The ladder’s center of mass is L/3 from the lower end along the lengthy of the ladder. A fire fighter of mass M=72 kg climb the ladder until her center of mass is L/2 from the lower end. What are the magnitude of the forces on the ladder from the wall and the pavement?

In a closed system, the total energy prior to an energy transformation is the total energy after. a. equal to b. unrelated to c. greater than d. less than

•• al and bert are jogging side-by-side on a trail in the woods at a speed of 0.75 m/s. suddenly al sees the end of the trail 35 m ahead and decides to speed up to reach it. he accelerates at a constant rate of 0.50 m/s2, while bert continues on at a constant speed. (a) how long does it take al to reach the end of the trail? (b) once he reaches the end of the trail, he immediately turns around and heads back along the trail with a constant speed of 0.85 m/s. how long does it take him to meet up with bert? (c) how far are they from the end of the trail when they meet?

The seven sisters, seven stars located more than 400 light-years away in the taurus constellation can be seen here with venus and another constellation, orion. the seven stars stay grouped together but seem to move, like the planet venus. why do stars seem to move like planets in the night sky?