Answer:
Al's mass is 102.92 kg
Explanation:
As there are no external forces in the horizontal direction, the horizontal net force must be zero:
As the force is the derivative in time of the momentum, this means that the horizontal momentum is constant:

where the suffix i and f means initial and final respectively.
The initial momentum will be:

But, as they are at rest, initially


So, this means:

We know that the have an combined mass of 195 kg:
.
so:
.





Now, we can use the values:


where the minus sign appears as they are moving at opposite directions


and this is the Al's mass.
Answer:
The correct option is B. 7.5 * 10¹⁴ Hz
Explanation:
Frequency = (speed) / (wavelength)
= (3 x 10⁸ m/s) / (4 x 10⁻⁷ m)
= (3/4 x 10¹⁵) ( m / m - s )
= (0.75 x 10¹⁵) /sec
= 7.5 x 10¹⁴ Hz
= 750,000 GHz
Answer:
I think the answer is B
There is no specific reason