Compare and contrast repetition and replication in a science investigation

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?

By what primary heat transfer mechanism does the sun warm the earth?

If 25 ml of each of the liquids in the answer choices below were poured into a 100 ml beaker, which would form the second from the bottom layer? a. sea water – density of 1.024 g/ml b. mineral oil – density of 0.910 g/ml c. distilled water – density of 1.0 g/ml d. petroleum oil – density of 0.820 g/ml