Answer:
Energy, E = 178.36 J
Step-by-step explanation:
It is given that,
Mass 1,
![m_1=4\ kg](https://img.qammunity.org/2020/formulas/physics/college/aukq3sw6ttdf6m98a7ax6ysqgcb7npyrwf.png)
Mass 2,
![m_2=4\ kg](https://img.qammunity.org/2020/formulas/physics/high-school/jtwph6f7jzglmmyv6hwqh9b8lctljlo3po.png)
Mass 3,
![m_3=6\ kg](https://img.qammunity.org/2020/formulas/physics/high-school/c2yampfh8tuse8ijtnllniv7vqvg89ud32.png)
Height from which they are dropped, h = 1.3 m
Let m is the energy used by the clock in a week. The energy is equal to the gravitational potential energy. It is given by :
![E=(m_1+m_2+m_3)gh](https://img.qammunity.org/2020/formulas/physics/high-school/hnen1sfz27ml0qkod07s7gnvyqemp8bbuh.png)
![E=(4+4+6)* 9.8* 1.3](https://img.qammunity.org/2020/formulas/physics/high-school/ar9q6tq55zseelkhrvrr1p4ex1txvdbg3h.png)
E = 178.36 J
So, the energy used by the clock in a week is 178.36 Joules. Hence, this is the required solution.