Answer:
The height of the cliff is, h = 78.4 m
Explanation:
Given,
The horizontal velocity of the projectile, Vx = 20 m/s
The range of the projectile, s = 80 m
The projectile projected from a height is given by the formula
<em> S = Vx [Vy + √(Vy² + 2gh)] / g
</em>
Therefore,
h = S²g/2Vx²
Substituting the values
h = 80² x 9.8/ (2 x 20²)
= 78.4 m
Hence, the height of the cliff is, h = 78.4 m
Answer:
So the mass of the second object M will be 1.951 kg
Explanation:
We have given mass of the first object 
and its velocity 
Mass of the second object 
it is at rest so its velocity 
From conservation of momentum we know that
Initial momentum = final momentum
So 
M = 1.951 kg
Answer:
C.when the nucleus decays
Explanation:
In chemical reactions, the outermost electrons of atoms are re-arranged somehow without the involvement of the nuclei of the participating atoms of the elements.
Nuclear reactions causes changes within the atomic nucleus. For every atomic nucleus, a specific neutron/proton ratio ensures stability. When the stability ratio differs an atom becomes unstable and splits into one or more other nuclei with the emission of small particles of matter. This is what radioactivity entails.
Answer
The nail will become an electromagnet.
Explanation
When the switched is closed , a current will flow in the insulated wire. Then the current flows through the coil around the iron nail, it will induce am magnetic filed inside the nail. The nail becomes a magnet because it is made of magnetic material. As long as there is current flowing through the current, there nail will remain a magnet.
