Motion and Time — Science STD 7 — Question

Why do we get instant energy from glucose?

People say that nothing goes waste in a forest. Can you explain, how?

Give one use each of a concave and a convex mirror.

Aanya goes from her home to school. On the first day, she walks 4 km in 50 minutes and on the next day, she goes by cycle and covers the same distance in 15 minutes.
(i) Find her walking speed in m/s.
(ii) Find her cycling speed in km/h.
(iii) What is her average speed through the entire trip?

Untreated human excreta is a health hazard. Explain.

Last Sunday Girish's mother, Priyanka was preparing the dinner in her kitchen for Girish and his father. Both of them were feeling so much hungry and they sat ideally on their respective chairs and having empty plates and spoons on their dinning table. They were shouting like a 5 years old child that they wanted the dinner so eagerly to fulfil their stomach. After sometime, Girish's mother served the cooked food to both of them and when Girish was just about to eat the rice with the help of spoon, he noticed that the spoon has such a shining surface that it reflected the light rays incident on it.
(i) Explain the importance of shining surface in the reflection of light.
(ii) Name the type of spherical mirror represented by the shining steel spoon.
(iii) Mention the values shown by Priyanka here towards her family

Label the following parts in Figure and name them.

1. The largest gland in our body.
2. The organ where protein digestion starts.
3. The organ that releases digestive juice into the small intestine.
4. The organ where bile juice gets stored.

Read the passage and answer the questions :
During a school science event, students watched a solar eclipse. Some used solar viewing goggles, some projected the image on a wall using a mirror, and one student tried looking directly at the eclipse.
Q.1. Which method of solar eclipse viewing is unsafe?
(a) Using a mirror to project the image
(b) Using solar eclipse glasses
(c) Watching a live stream online
(d) Looking at the eclipse directly with the naked eye
Q.2. Why does the Sun temporarily disappear during a total solar eclipse?
(a) The Earth comes between the Sun and the Moon
(b) The Sun moves behind the Moon
(c) The Moon blocks sunlight from reaching Earth
(d) The Sun burns out temporarily
Q.3. What is the correct alignment of celestial bodies during a solar eclipse?
(a) Earth - Moon - Sun
(b) Moon - Sun - Earth
(c) Sun - Earth - Moon
(d) Sun - Moon - Earth

State the importance of air pressure. Give reasons for air pressure.

Why should oils and fats be not released in the drain? Explain.