Answer:
Compasses are mainly used in navigation to find direction on the earth. This works because the Earth itself has a magnetic field which is similar to that of a bar magnet. The compass needle aligns with the Earth's magnetic field direction and points north-south. Also, In a magnet all the domains are oriented in the same direction. In the case of a nail, the domains can be aligned in the same direction causing the nail to become magnetic. That is because if you hang a bar magnet from a thread, the north pole will point to magnetic north. When you bring one north pole close to another north pole they repel each other. You can feel the two magnets pushing each other apart.
Correct answer choice is :
C) To see if samples contain the target dna
Explanation:
In many North American rivers, populations of various kinds of non-native cyprinid fishes are present, including black carp, grass carp, bighead carp, silver carp, common carp, and goldfish. All six of these classes are found in the Mississippi River basin and following their aggression has shown complex, especially where wealth is low. The bighead carp is a species of freshwater fish, one of several Asian carps. It is one of the most intensively exploited fishes in aquaculture, with a yearly global product of over three million tonnes in 2013, mostly from China.
Answer:
1.31022×10⁻³⁴ kg
Explanation:
Difference in energies = 1189.4-1115.7 MeV = 73.7 MeV
Convert this energy to Joules
1 MeV = 1.6×10⁻¹⁹ J
73.7 MeV = 73.7×1.6×10⁻¹⁹ J = 117.92×10⁻¹⁹ J
c = Speed of light = 3×10⁸ m/s
From Einstein's equation
E = mc²
∴ Difference in their masses is 1.31022×10⁻³⁴ kg
Answer:
5 cm .
Explanation:
Wave length of sonar waves λ = 1390 / 512
= 2.715 m
For waves getting reflected from both layers of the coating , undergoing phase reversal , net change will be zero .
For destructive interference
path diff = ( 2n+1) λ / 2
2μt = ( 2n+1) λ / 2
2 x 13.5 x t = ( 2n+1) λ / 2
for minimum thickness
n = 0
2 x 13.5 x t = λ / 2
2 x 13.5 x t = λ / 2
t = λ / (2 x 27)
= 2.715 / 2 x 27
= .05 m
5 cm .
