A teacher asked her students to design a hot pack. The desired criteria and constraints for the hot pack are as follows:
its temperature should remain at or above 90°C for as long as possible
its temperature should remain as constant as possible
it should be durable and leak proof
it should fit inside shoes, gloves, or a pant pocket
The students were instructed to mix calcium chloride crystals in plastic bags filled with water. They were split into three groups, and each group created a design. Each design used a different amount of calcium chloride crystals. The table shows the hot pack designs created by the three groups.
Amount of Time at 90°C (minutes) Variation in Temperature (°C) Durability of Pack (hours) Size of Pack
Design 1 20 0-5 24 10 cm × 6 cm
Design 2 40 0-7 20 10 cm × 6 cm
Design 3 30 0-7 15 8 cm × 5 cm
How could the designs be combined to best meet the criteria and constraints?
A.
time at 90°C of Design 3 and durability of Design 1
B.
time at 90°C of Design 2 and durability of Design 1
C.
temperature variation of Design 3 and size of Design 2
D.
temperature variation of Design 2 and size of Design 3
Answers: 3
Biology, 21.06.2019 18:50, Angel13613
Ectocarpene is a volatile, sperm cell-attracting material released by the eggs of the seaweed ectocarpus siliculosus. its constitution is all the double bonds are cis, and the absolute configuration of the chirality center is s. draw a stereochemically accurate representation of ectocarpene.
Answers: 3
Biology, 22.06.2019 02:30, mahaypatto
{answer found. it's (3 ) }which statement describes the cell cycle? (1)the cell cycle is a process in which one cell divides into four genetically different cells. (2)the cell cycle is a process in which one cell divides into two genetically different cells. (3)the cell cycle is a process in which one cell divides into two genetically identical cells. (4)the cell cycle is a process in which one cell divides into four genetically identical cells.
Answers: 1
Biology, 22.06.2019 10:30, loganfreeman04
Nkentucky, intoxicating beverages (beer, whiskey, wine, etc.) are involved to some extent in approximately % of collisions fatal to pedestrians.
Answers: 3
A teacher asked her students to design a hot pack. The desired criteria and constraints for the hot...
Mathematics, 08.09.2021 05:10
Biology, 08.09.2021 05:10
Mathematics, 08.09.2021 05:10
Mathematics, 08.09.2021 05:10
Mathematics, 08.09.2021 05:10
Biology, 08.09.2021 05:10