Which of jackie’s actions would violate proper laboratory safety? check all that apply. a. taking off his gloves to pick up large shards of glass b. replacing a beaker that had a crack in the top c. placing hazardous waste in the chemical bin d. using his mouth to pipette the correct amount of solution into a pipette e. moving his chemicals away from the lit bunsen burner

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

You notice a very one-dimensional-thinking snail crawling along one rail of a railroad track. naturally, you remove it to a safer place. but before you do, you observe it as it moves from position xi = -92.9 cm to position xf = -64.9 cm along the rail, as measured from a point where one rail abuts the next. what is the snail\'s displacement δx in centimeters?

1400 kg car has a speed of 27 m/s. if it takes 7 s to stop the car, what is the impulse and the average force acting on the car?