watashiwa science

how does the thin carrier of a bag hurt a person's hand than a bag with thick carrier? explain in terms of pressure

Answer explanation

1. As the bag has thinner handles, the handle has lesser surface area in contact with the hand.
2. Since pressure is equal to the force exerted per unit area,
3. Higher pressure is exerted on the hand by the thin handles of the bag
4. Thus, the person's hand will hurt more.

in terms of energy transfer, how does a pendulum stop swinging?

Answer explanation

1. As the pendulum swings through the air,
2. air resistance converts kinetic energy of the pendulum to thermal energy and sound energy.
3. Eventually, all the kinetic energy is converted to thermal energy and sound energy,
4. causing the pendulum to come to a rest.

Why is the small intestine longer?

Answer explanation

The small intestine is longer because
1. more time to absorb water and nutrients
2. greater surface area than large intestine for more efficient absorption of water and nutrients.

what happens to a students with a lower red blood cell count than normal?

Answer explanation

When a student has a lower RBC count than normal,

1. The student will feel more tired
2. will not be able to carry out strenuous tasks
3. since he has fewer RBC to transport oxygen around his body
4. This leads to a lower rate of respiration and less energy produced.

Why does the root hair cell have a long protrusion?

Answer explanation

the root hair cell has a long protrusion to
1. increase surface area to volume ratio,
2. allowing water to be absorbed at a faster rate

why is a transport system needed?

Answer explanation

A transport system is needed to
1. transport oxygen and digested food to the cells of the body

2. 2. and waste products out of the cell quickly
   3. otherwise, the cells may die from starvation or be poisoned by the waste products.

why to veins require valves?

Answer explanation

Veins require valves as
1. blood flows slower in the vein
2. so blood pressure is lower
3. the valves help to prevent backflow
4. and ensure unidirectional flow of blood

Farmers remove the outermost layer of the tree trunk, producing bigger fruits. However, when too much is removed, the tree died. Why?

Answer explanation

1. The phloem carries sugar made by the leaves.
2. Removing the outermost layer of the tree trunk removes some of the phloem
3. and causes less sugar to be transported to the fruits, to produce bigger fruits.
4. If too much phloem tissue underneath the bark is removed,
5. sugar will not be transported to the bottom of the tree,
6. Hence the tree will die.

explain osmosis in roots

Answer explanation

1. higher concentration of water molecules are usually present in the soil than in the root cells of plants.

2. The root cells have a partially permeable cell membrane. 3. Water enters the root cells from the soil by osmosis. 4.Water moves across the roots from cell to cell by osmosis.
5. Water is transported to the rest of the plant via the xylem.

An athlete drank a glucose solution just before a race to get a quick dose of energy. Give a reason for this!

Answer explanation

(glucose is simple sugars)

As glucose does not need to be digested, it is rapidly absorbed into the bloodstream to provide immediate energy the runner needs.