# Apparent Weight and Newtons Second law Problems

• thisismyacc
In summary: Hope this helped. :)In summary, the first problem involves an elevator with an acceleration of 3.36 m/s^2 and a person with a mass of 64.2 kg. The apparent weight can be calculated using the formula m(g-a). For the second problem, involving Blocks A and B, a free body diagram should be created to show the forces acting on the system. The force exerted by Block A on Block B can be calculated using the equation F=m*a. For the third problem, involving Bob pushing a barrel with a mass of 6.8 kg, a free body diagram should also be created and the equation F=ma can be used to determine the initial force.
thisismyacc

## Homework Statement

1. The first problem states that an elevator moves downwards with an acceleration of 3.36 m/s^2 with someone inside that has the mass of 64.2 kg. Now what is the apparent weight?

2. Blocks A and B are right next to each other. If 5.1 N were applied on block A, calculate the force block A applies onto block B assuming they stay next to each other the whole time. Block A is 3.1 kg and Block B is 5.3 kg. There is no friction involved.
A B
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3. Bob pushes a barrel that is 6.8kg 8.5m. He exerts 50N of force and the final velocity is 15 m/s, what is the initial force? No friction involved.

## Homework Equations

1. m(g-a), not sure?

2. No idea

3. (F/m)- g = a plug a into another equation?

## The Attempt at a Solution

1. 414.09 kg, not sure if right
2. No idea
3. Vi= 16.33 m/s, not sure if right

you need to get into the habit of creating Free body diagrams to show all the forces on your system, these will help you understand the physics of more complex problems in the future.

1)
Force in Y = -mg - ma = - Weight

2) again sum the forces in the x direction

I have no idea what you mean for 2), and for number 3 did I use the correct formula to account for gravity or am I supposed to leave gravity out?

for 2)
what you got to do is draw the FBD. It should contain the initial force applied in x direction and the contact force between the two blocks (say C).
Then plug in the equations using this basic relation F=m*a and solve the problem.

The free body diagram is VERY IMPORTANT. It seems insignifigant but it is very useful. Before you can use any equations you have to add all of the forces on each axis. When you are done with that step you will have one NET force in the x direction and one NET force in the y direction. THEN you can go ahead and plug and chug.

## 1. What is apparent weight?

Apparent weight is the weight perceived by an object or person in a non-inertial frame of reference, such as an accelerating elevator or a rotating amusement park ride. It is different from actual weight, which is the force of gravity acting on an object's mass.

## 2. How is apparent weight related to Newton's Second Law?

According to Newton's Second Law, the net force acting on an object is equal to its mass multiplied by its acceleration. In the case of apparent weight, the acceleration experienced by the object or person in a non-inertial frame of reference is what causes the difference between actual weight and apparent weight.

## 3. How do you calculate apparent weight in a problem?

To calculate apparent weight in a problem, you need to first identify the non-inertial frame of reference and the acceleration acting on the object or person in that frame. Then, you can use the formula F=ma to calculate the apparent weight, where F is the net force, m is the mass, and a is the acceleration.

## 4. What are some common examples of apparent weight problems?

Some common examples of apparent weight problems include an elevator accelerating upwards or downwards, a car making a sharp turn, or a roller coaster going over a loop. In these situations, the apparent weight of the objects or people inside the elevator, car, or roller coaster will be different from their actual weight due to the acceleration acting on them.

## 5. How does apparent weight affect our daily lives?

Apparent weight may not seem like a significant concept in our daily lives, but it actually plays a role in many activities such as driving a car, riding a bike, or even walking. When we experience different types of acceleration, our apparent weight changes and this affects our balance and movement. Understanding apparent weight can also help us design and improve amusement park rides and other forms of transportation.

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