Question

The potential energy of an object varies jointly with the mass of the object and the height of the object off the ground. A 25-kg object has 980 joules of potential energy when it is 4 meters off the ground. Another object has 150 joules of potential energy at 3 meters off the ground. What is the mass of the second object? Round to two decimal places.

Answer 1

Answer:

The mass of the second object is 5.10 Kg

Explanation:

We are given that the potential energy varies directly with both the mass of the object and its height

This means that:

P.E = kmh .......................> I

where:

P.E is the potential energy

k is the constant of proportionality

m is the mass of the object

h is the height of the object

We are given that a 25-Kg object has 980 joules of potential energy when it is 4 meters off the ground

We will substitute with these givens equation I and solve for k as follows:

P.E = kmh

980 = k × 25 × 4

k = 9.8

This means that:

Potential energy = 9.8 × mass of object × height of object ...........> II

Now, we want to get the mass of an object knowing that its potential energy is 150 joules and its height is 3 meters off the ground

We will substitute in equation II and solve for the mass as follows:

Potential energy = 9.8 × mass of object × height of object

150 = 9.8 × mass of object × 3

mass of object = 5.102 Kg which is 5.10 Kg rounded to two decimal places

Hope this helps :)

Answer 2

Answer:

This is physics. By the way look the explanation.

Step-by-step explanation:

The formula of Potential Energy is E=mgh, where m is the mass of the object, g the gravitational, and h the height of the object. Given that the potential energy of the object is 150 Joules at 3 meters height, Represent m=E/(g*h), considering g=9.8 m/s^2(Because this value was used for the first object), we get m=150/9.8/3=5.102

Rounding to 2 decimals` 5.10 kg