HRS - Ask. Learn. Share Knowledge. Logo

Questions in physics

[Done] Given that the speed of the particle is 4 \hat{a}_x m/s in a region where E = 20 \hat{a}_y V/m and B = B_0 \hat{a}_z wb/m^2, determine the value of B_0 such that the velocity of the particle remains constant.

[Done] 1. Situation: Sarah has a glass of juice that she forgot to drink and left it on the table overnight. When she checked it the next morning, the level of juice in the glass had decreased. What happened to the volume of the juice? a) It increased. b) It decreased. c) It remained the same. d) It evaporated completely. 2. Situation: James has a balloon filled with air. He decided to squeeze the balloon gently. What change did James observe in the balloon? a) The balloon's shape remained the same. b) The balloon's volume increased. c) The balloon's volume decreased. d) The balloon's volume remained the same.

[Done] Listen. Newton's third law states that for every action, there is an equal and opposite A) reaction. B) gravity. C) acceleration. D) pull.

[Done] Select the correct answer. A car has a kinetic energy of [tex]$1.9 \times 10^3$[/tex] joules. If the velocity of the car is decreased by half, what is its kinetic energy? A. [tex]$2.2 \times 10^2$[/tex] joules B. [tex]$4.7 \times 10^2$[/tex] joules C. [tex]$5.2 \times 10^2$[/tex] joules D. [tex]$5.8 \times 10^3$[/tex] joules

[Done] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Done] SECTION B: THEORY INSTRUCTION: ANSWER ANY THREE QUESTIONS IN THIS PART 1. a. i. State two advantages of alcohol over mercury as a thermometric liquid. a. ii. When the bulb of a thermometer is placed in a beaker of hot water, the level of the mercury first falls and then rises gradually. Explain this observation.

[Done] 1. A coolie is moving on a road with a luggage on his head. Does he perform work against the force of gravity? Give reason for your answer. 2. The moon is revolving around the earth in a circular path. How much work is done by the moon? 3. Give reasons for the following: (a) No work is done if a man is pushing against a wall. (b) Hammer drives a nail into the wood only when it is lifted up and then struck. (c) A horse and a dog are running with the same speed. Which one of them has more kinetic energy than the other? (d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work. 4. Name the form of energy to which potential energy can change. 5. Is it practically possible to convert a form of energy completely into another useful form? Give reason.

[Done] In a car, how does an air bag minimize the force acting on a person during a collision? A. It increases the change in momentum of the person. B. It decreases the change in momentum of the person. C. It increases the time it takes for the person to stop. D. It decreases the time it takes for the person to stop.

[Done] In which situation is work being done? A. No force is applied. B. The force does not result in displacement. C. The force and displacement are perpendicular to each other. D. The force and displacement are in the same direction.

[Done] In addition to how much force Earth exerts on the object, which features of an object affect its weight? A. mass and location of the object B. shape and location of the object C. location of the object and how much energy the object has D. mass of the object and how much energy the object has