the magnitude of charge=q=8.76 x 10⁻⁵C
Explanation:
the magnetic force Fm is given by
Fm= q V B sinθ
q= charge
v= velocity= 2.5 x 10⁴ m/s
B= magnetic field strength= 8.1 x 10⁻²T
Fm= magnetic force= 7.5 x 10⁻² N
θ=25°
so 7.5 x 10⁻² =q (2.5 x 10⁴ ) (8.1 x 10⁻²) sin25
q=8.76 x 10⁻⁵C
A.) <span>If no unbalanced force acts upon the house of cards, then it will remain standing forever.
[ Other Statements doesn't make any sense in Physics, they can be true in some situation & can't be false, option A is the only answer ]
Hope this helps!</span>
For a reaction to occur, energy must be absorbed to break chemical bonds
<u>Explanation:</u>
Reactions can be classified as chemical reaction, nuclear reaction, thermal reaction. So in these three reaction types, the nature of energy will only be varying.
But in order to execute a reaction, there should be breaking of existing bonds and then formation of new bonds. So for breaking of the bonds of reactants, energy should be absorbed from the surrounding.
Then the extra energy will be released after forming the products. Thus, the process of absorption of energy will lead to endothermic process and the process of releasing of energy will lead to exothermic reaction. So for a reaction to occur, energy must be absorbed to break the chemical bonds.
