Answer:
Mass of bike = 38 kg.
Explanation:
Kinetic energy is given by the expression, 
, where m is the mass and v is the velocity.
Here speed of child riding bike = 6 m/s
Mass of child = 30 kg
Total kinetic energy = 1224 J
Let the mass of bike be, m kg
So, total mass of child and bike = (m + 30) kg
Substituting,
So, mass of bike = 38 kg.
Answer:
Explanation:
The specific heat of gold is 129 J/kgC
It's melting point is 1336 K
It's Heat of fusion is 63000 J/kg
Assuming that the mixture will be solid, the thermal energy to solidify the gold has to be less than that needed to raise the solid gold to the melting point. So,
The first is E1 = 63000 J/kg x 1.5 = 94500 J
the second is E2 = 129 J/kgC x 2 kg x (1336–1000)K = 86688 J
Therefore, all solid is not correct. You will have a mixture of solid and liquid.
For more detail, the difference between E1 and E2 is 7812 J, and that will melt
7812/63000 = 0.124 kg of the solid gold
Answer:
They are rechargeable
They have a longer life span
They are reusable
Explanation:
Lead acid accumulators and leclanche cells are types of electrochemical cells.
Leclanche cells are primary cells. Primary cells produce chemical reactions through which the electric current generated is irreversible.
Lead Acid Accumulators are secondary cells in which electric current generated is reversible.
This makes lead acid accumulators reusable, more durable and they have a longer life span.
