Se apunta un rifle horizontalmente con mira a un blanco pequeño que está a 200m en el suelo. la velocidad inicial de la bala es de 500m/s. calcular:
¿qué tiempo dura la bala en el aire?
¿a qué altura del suelo estaba el rifle?

Ineed asap! list 3 examples in which friction us or makes things easier in our daily life. explain the effect of friction for each. *make sure you explain the effect of friction for each example! *

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

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?