Answer:
You didn't give the information needed for the answer bud
Explanation:
Answer:
-6112.26 J
Explanation:
The initial kinetic energy, 
is given by
} where m is the mass of a body and 
is the initial velocity
The final kinetic energy, 
is given by
where 
is the final velocity
Change in kinetic energy, 
is given by
Since the skater finally comes to rest, the final velocity is zero. Substituting 0 for and 12.6 m/s for and 77 Kg for m we obtain
From work energy theorem, work done by a force is equal to the change in kinetic energy hence for this case work done equals <u>-6112.26 J</u>
Answer:
due to the magnetic field
Explanation:
magnetic field is the same in the vacuum
Answer:
525 Bq
Explanation:
The decay rate is directly proportional to the amount of radioisotope, so we can use the half-life equation:
A = A₀ (½)^(t / T)
A is the final amount
A₀ is the initial amount,
t is the time,
T is the half life
A = (8400 Bq) (½)^(18.0 min / 4.50 min)
A = (8400 Bq) (½)^4
A = (8400 Bq) (1/16)
A = 525 Bq
