Nuclear fusion requires MCQ with Answer and Explanation

Explanation:
When an object (like a jet plane) exceeds the speed of sound (Mach 1), it overtakes the sound waves it produces. These sound waves pile up behind the object, superimposing constructively to form an intense, cone-shaped pressure wave called a shock wave. When this high-pressure cone sweeps over an observer on the ground, they hear a loud 'sonic boom'.

Explanation:
Speed constant, so kinetic energy (½mv²) constant. Velocity, acceleration, momentum change direction.

Explanation:
0.050 has two significant figures? Wait, leading zeros not significant. 5 and trailing zero? The trailing zero after decimal is significant if it indicates precision. 0.050: first non-zero is 5, the zero after 5 is significant because least count 0.001, so it shows no thousandths. So digits 5 and 0? Actually '0.050' - the first zero after decimal is not significant, 5 is significant, last zero is significant. So two significant figures? Let's check: 0.050 has two significant figures (5 and trailing zero). But if least count 0.001 cm, reading should be 0.050 cm meaning no further digits. That is 2 SF. But options: I need to set accordingly. I'll just make a different question. Too messy. I'll skip and add another. To save time, I'll replace with a sure question.