Geologists do not use a minerals color or streak to identify them because some minerals can have the same streak and color but the correct answer is
b) color
Answer: The correct answer is option B.
Explanation:
Mass of the sled = 10 kg
Initial speed of the sled = 2 m/s
Kinetic energy of the sled = 

Work done by the sled = 20 joules
The work done by the friction will be in opposite direction and equal to the magnitude of the work done of the sled that - 20 J.
Hence, correct answer is option B.
Answer:
Number of turns in secondary will be 7
Explanation:
We have given primary voltage 
Number of turns in the primary is 
Secondary voltage is given 
We have to find the number of turns in secondary
We know that 
So 

As the number of turns can not be in decimal so number of turns will be 7
The seat belt is applying a force in the opposite direction.
Answer : 12.7 cm = 127. mm