Answer:
Average speed = distance/time
From 1 to 9 seconds:
Distance covered = 1 - 0.2 = 0.8 km
Time = 9 - 1 = 8 sec
Average speed = 0.8 km / 8 sec
Average speed = 0.1 km/s .
The average speed for the whole test is 1.6 km / 20 sec = 0.08 km/sec. A graph of speed vs time would average out as a horizontal line at 0.08 km/sec from 1 sec to 21 sec. The area under it would be (0.08 km/s) x (20 sec) = 1.6 km.
Surprise surprise ! The area under a speed/time graph is the distance covered during that time !
In closing, I want to express my gratitude for the gracious bounty of 3 points with which I have been showered. Moreover, the green breadcrust and tepid cloudy water have also been refreshing.
Explanation:
Option (D) is the correct one.
In order to increase the amount of work done, we need to increase the force applied to the object.
Answer:
a) 17 km
b) 9 km
Explanation:
The distance is the length of the path.
A to C: 5 km
B to C: 4 km
C to B: 4 km
B to C: 4 km
Total distance = 5 km + 4 km + 4 km + 4 km = 17 km
Displacement is the difference between the starting point and ending point.
Displacement = 9 km − 0 km = 9 km
D. It must be able to be magnetized
Explanation:
The requirement for a core to be used in an electromagnet is that it must be able to be magnetized.
An electromagnet is a type of magnet produced by electricity.
- They typically run and produce magnetic fields in the vicinity of electrical currents.
- These magnets are not permanent magnets.
- When the electrical current is removed, the magnetic property of the substance is lost.
- The core of an electromagnet is usually made up of a material that can easily be magnetized in the presence of magnetic fields.
- Some of the materials used are cobalt, iron, nickel.
learn more:
Electromagnet brainly.com/question/2191993
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D. There is a known constant concentration of C14 in Nature. As we consume living things to survive our bodies (made of carbon) stop replenishing our body's carbon (we stop eating) and start to decay. Since we know the 1/2 life of C14 and the ratio of C14 to normal C12 we can determine fairly accurately how long ago a thing stopped consuming carbon (e.g. when it died)
