Answer:
1) 2.44 joules
2) 7.73 m/s
3) 7.6 joules
Step-by-step explanation:
Kinetic energy (K) of a particle is:
(1)
with m the mass, and v the velocity
1) Because we already now velocity on A (va) and the mass of the object we can calculate its kinetic energy:
![K_(a)=(mv_(a)^(2))/(2)=((0.338kg)(3.8(m)/(s))^(2))/(2)=2.44J](https://img.qammunity.org/2021/formulas/physics/high-school/5d8q059ck8toirsi89tkqf2au72ftoaqys.png)
2) Because on B we know mass and kinetic energy we should solve (1) for v and use our values to find the velocity on B:
![v_(b)=\sqrt{(2K_(b))/(m)}=\sqrt{(2(10.1J))/((0.338kg))}=7.73(m)/(s)](https://img.qammunity.org/2021/formulas/physics/high-school/fhsn9jxtz8usk9rymcr3imrzt7txz0swym.png)
3) Work-energy theorem states that the change of kinetic energy of an object is equal to the total work done on it, so:
![W=K_b-K_a=10.1J-2.44J= 7.6J](https://img.qammunity.org/2021/formulas/physics/high-school/tqwts5qlekurip3av2yyor4n75hbfour75.png)