Question

Pls help me solve these two questions!!! Tq​

Answer 1

Part A would be 80 Joules and Part B would be 20 meters.

Step-by-step explanation:

For Part A:

The first step is to convert the mass to SI units.

400 g = 0.4 kg

Next, we need to know that the law of conservation of energy states that the total energy of an isolated system is conserved. In this case, it means that the total energy at the bottom, where kinetic energy is greatest, will be equal to the total energy at the top, where gravitational potential energy is greatest.

Max Gravitational Potential Energy = Max Kinetic Energy

Max Gravitational Potential Energy =
`(1)/(2) mv^(2)`

Max Gravitational Potential Energy =
`((1)/(2) )(.4kg)(20m/s)^2` = 80
`J`

For Part B:

We need to once again set gravitational potential energy to kinetic energy, only this time we use the GPE equation and solve for height. We already solved for the kinetic energy so we just plug everything in and solve.

`mgh = (1)/(2) mv^(2)`

`(.4kg)(10m/s^(2) )h = 80J\\h = 20m`