Physics Answers

 An 85 kg person is parachuting and experiencing a downward acceleration of 4.5 m/s2. The

mass of the parachute is 4.0 kg.

a) (10%) Draw free body diagram.

b) (10%) What is the upward force on the open parachute from the air?

c) (10%) What is the downward force on the parachute from the person?

 A positive point charge Q is placed on the −x-axis at x = −a, and a negative point charge −Q is placed on the +x-axis at x = a. A positive point charge q is located at some point on the +y-axis. (a) In a free-body diagram, show the forces that act on the charge q. (b) Find the x- and y-components of the net force that the two charges Q and −Q exert on q. (Your answer should involve only k, q, Q, a and the coordinate y of the third charge.) (c) What is the net force on the charge q when it is at the origin (y = 0)? (d) Graph the x component of the net force on the charge q as a function of y for values of y between −4a 

You are asked by your mother to cook pork nilaga. You have only an ordinary ketttle to use for cooking.she even reminds you to save energy because we are in a state of pandemic due to covid -19. Saving resources nowadays is a must because we are not sure of the worl's economy.As a student of Physical Science and with your knowledge of properties of matter in relation to intermolecular forces, how are you going to perform your task in sucb a way that energy in not wasted?

If in the previous problem (problem 7). If charge 𝑞1 = −3.20 × 10−19𝐶 is added and placed at a distance (¾) R from 𝑞1. Find the magnitude and direction of net force on 𝑞1

Two points charges Q and +q (where q is positive) produce the net electric field. The field points parallel to the line connecting the two charges. What can you conclude about the sign and magnitude and Q? Explain your reasoning. If the lower charge were negative instead, would it be possible for the field to have the direction? Explain your reasoning.

Situation C: Two students are sitting on a swing. Student A is 40 kilograms while student B is 50 kilograms.

1) Who will swing with greater acceleration: student A or student B? Justify your answer.

2) What physical quantity was changed in this situation?

3) What relationship exists between the varying physical quantity and acceleration?

4) Combining the ideas from the three situations, how do state the law of acceleration?

Situation B: Suppose you are biking one fine day. You have seen that there is a pile of leaves in front of you. Wind blows causing the pile of leaves to spread.

1) How would you compare the effect of a light breeze of wind and a huge amount of wind on that pile of leaves?

2) What physical quantity was varied in this situation?

3) What relationship exists between the varying physical quantity and acceleration?

Situation A: You are on a trip with your friends. Then suddenly, the car stopped because it ran out of gas. To avoid causing traffic, the car must be pushed to the side of the road.

1) When will the car move (accelerate) faster, when only 1 person pushes it or when more persons push it? Justify your answer.

2) What physical quantity was changed in this situation?

3) What relationship exists between the varying physical quantity and acceleration?

A hole of cross-sectional area 100 c m 2 is cut in a piece of steel at 20 o C . What is the area of the hole if the steel is heated from 20 o C to 100 o C ? The coefficient of linear expansion of steel is 1.10 × 10 − 5 o C

Study it. In which of it does the boy exerted a greater force?

A. The boy pulling the rope tied in the wall

B. The boy pulling the rope tied in the elephant

Explain your answer