physics homework help problems

physics homework help problems

Solving Physics Problems: A Comprehensive Guide

1. Introduction to Problem-Solving in Physics

There are 3 key points in the solving approach: SnS. What is the System under consideration – this could be a set of particles, it could be an equal freedom body. What are the forces acting on it – there are four realistic ones and, by convention, the force due to gravity is called. Free Body Diagrams are diagrams showing the forces. What strategy will solve the Question – translate the question out of the words and into an equation for you to solve. It is very difficult to start solving a mechanics problem without these 3 points, but the physics is examined in this booklet will guide you. For example, you cling to your pen and hoist yourself up to balance on the door handle. To save your blushes, I won’t ask you how you solve this one! So, see what can be done. The accompanying answers should help you.

Physics is a subject renowned for being complex, requiring deep thought. It also explains the operation of all natural forces and many human-made inventions. There are many possible ways to tackle the problems, but all methods will benefit from a good understanding of problem-solving techniques. The ultimate aim of these techniques is to help you solve the mechanics, something that you may be assessed on in a homework assignment, laboratory report, or forthcoming examinations. The answer is less important than the process that takes you there. Your reasoning of a question will provide your tutors with a much better understanding of your level of understanding than simply seeing if your answer is different from the ‘model solution’. Ask questions about anything in this booklet or anything that you have learned in the first year of your degree.

Section 1: Introduction to Problem-Solving in Physics

2. Key Concepts and Formulas for Common Problems

Some important facts regarding velocity, v, and acceleration, a, are when v is constant, so is a. Hence, a non-accelerated velocity is a constant velocity (a discussion about linear motion). Moreover, when v is constant, flux a acting to equal the vector sum of the forces acting on the object, or simply ΣF = ma. Here, ΣF is the total vector sum of all the forces acting on the object with mass m. When gravity contributes to the axis of motion, the acceleration a = g. This is only true when the y-direction is pointed downward (and hence our coordinates too); otherwise, a = -g. If the object is y = h meters above the ground, so h – y = 0, the gravitational potential energy of the object is mgh, where property g denotes the magnitude of the gravitational acceleration and h is the vertical height or the elevation above the target. Generally velocity is a vector equals to v = (vx i + vy j), while the acceleration is a vector too and equals to a = (ax i + ay j), the object’s mass is m, and the time for travel can be found as t = x/vx0. As we can see from the list above, it is a good “list” of object features you may need for three-dimensional motion problems in pre-college and college tests.

Ideal projectiles are those with no air resistance acting on the motion. Generally, we have an initial velocity in a specified direction, an angle to the horizontal, and an acceleration of gravity. The direction of gravity is vertically downward and its magnitude is g = 9.80 m/s^2. A position vector of a three-dimensional coordinate system (in a plane perpendicular to the direction of gravity in our case) is commonly expressed as r = (xi + yj), where i and j are the unit vectors along the x- and y-directions, respectively. This representation yields to x and y components of r: x = x0 + vx0t and y = y0 + vy0t – 1/2gt^2. Here x0 and y0 is the initial position of the object, while vx0 and vy0 are the x and y components of initial velocity. Typically, the concept of t comes into a problem when you are asked to find it. If not, it is best to use symbolic solutions until you are ready to plug numbers in and solve for t. The variables in our above equations typically will represent some object of interest, which are position r = xi + yj, the velocity v = vx i + vy j (also consider the magnitude of the velocity), and the acceleration a = ax i + ay j.

3. Strategies and Techniques for Approaching Physics Problems

When applying these strategies, your first task is to make a list of the given quantities and the required quantities for the problem. Then you will use the given quantities and possibly some fundamental constants of nature, such as c, h, e, and… to obtain the required quantities. This toolkit will help you develop further the steps of the recommended steps for solving physics and engineering problems in Table 3-1. The first steps differ slightly from Fig. 1.1 because in general you may not have to use any given quantities to determine the required quantities. For example, to find the acceleration of a car you may not have to use any given quantities; you may make some reasonable assumptions about the problem and proceed to find out why acceleration is not a given quantity. In your study of physics and in your career you will continuously develop your skill and judgment as to which method is best to apply to each problem. Like any other skill, your ability will improve over time in direct proportion to the amount of work you put into it.

When faced with a physics problem, it is best to start with a plan. For most physics problems, a good way to proceed is to use the methodology that is summarized in Fig. 1.1. This approach can be developed further to help you solve many different types of problems in physics, chemistry, and engineering. You can think of this methodology as a type of “toolbox” that contains strategies for solving problems. The idea is to look at a wide range of problems and to identify the best strategy for approaching each problem. These strategies are systematic rather than ad hoc, making them applicable to various problems you might encounter.

4. Practice Problems with Step-by-Step Solutions

Problem 4 The body is moving in a straight line with a constant acceleration. Apply the constant acceleration equations to find what you desire.

Problem 3 Use the work-energy principle to identify the mechanical energy at the top of the track. What is the velocity with that energy at the bottom of the track?

Problem 2 While linear acceleration a causes an upward force of n = mg/(1 + a/g), the force required to keep constant linear velocity is just n = mg.

Solution Problem 1 The fundamental equations to relate circular motion quantities to linear motion quantities can be found in the section on circular motion. A car is going around a circle on level ground. The friction force supplies the centripetal force required for this. The friction force provides no positive acceleration in linear motion.

Problem 4 A 4.2 kg body is pulled with a constant force until it has been moved 3.0 m out to the right from its starting position. The pull is parallel to the sand so that the drag force is negligible. What does it move?

Problem 3 A sled course at a winter resort begins at the top of a steep, straight track and ends on a horizontal region. The sleds are launched with a speed of 12 m/s. In the absence of friction, what is the horizontal distance between the top and bottom of the track?

Problem 2 Suppose you are in an airplane on a runway driving down the runway at a constant acceleration of g. You do not see outside the airplane. How hard do you feel your back push against the seat? Suppose the airplane moves with a constant velocity after take off, but is still climbing at an angle theta. Then how hard do you feel your back push against the seat?

Problem 1 A car travels around a circle, its speed increasing at a constant rate. If the car goes once around the circle in a time of 50.864 seconds and travels 400.0 meters while reaching this speed, what is the minimum safe speed if the radius of curvature of the road is 75.00 meters?

5. Advanced Problem-Solving Strategies and Case Studies

There are numerous ways to approach the information presented in this section. The strategy may be to thoroughly understand the subject and the principles of the information presented, then apply the information to the case study. This could result in a detailed game plan or strategy aimed at avoiding pitfalls. Another strategy would be to take small pieces of the information and apply them to the case study bit by bit. Embarrassingly, we could have missed some additional solutions. Consider how you might take this advice and make it relevant to your study habits.

We’ve covered all the fundamentals, and we’ve provided case study, application-based questions in case studies where you’re asked to tie everything together, and there is no right answer to them. We have not shown any possible solutions or answers to the case studies. We want you to use what you’ve learned thus far and apply it. Challenge yourself to think outside the box. Case studies are used to demonstrate the practical side of problem-solving. You will see how different problem-solving strategies and tactics come into play in real-world scenarios. How are individuals being innovative? What may be done to overcome obstacles or avoid them altogether for those who are not? More significantly, how are you going to solve a problem on your own? No one depends on you now.

Advanced Problem-Solving Strategies