Physics Questions & Answers

Physics Questions & Answers concepts of momentum and impulse - CORRECT ANSWER- The impulse means that the bigger the force and the longer it acts for, the bigger the impulse will be. Impulse of force = change of momentum Define acceleration - CORRECT ANSWER- Acceleration is how quickly an objects velocity is changing, so if an object is moving around in a circle it is constantly accelerating because the direction is constantly changing Define efficiency - CORRECT ANSWER- Efficiency is the percentage of energy or power that is converted into useful energy or power because no devise is 100% efficient, the energy converted always converts into wasted energy eg heat Define speed - CORRECT ANSWER- A measure of how fast an object is travelling Define velocity - CORRECT ANSWER- A measure of how fast an object is travelling with direction Define weight - CORRECT ANSWER- Weight is a gravitational force Describe a manometer - CORRECT ANSWER- A manometer measures pressure difference. The height difference shows the extra pressure that the gas supply has in addition to atmospheric pressure called excess pressure. To find the overall pressure you add the excess pressure (height of Mercury in mm to the atmospheric pressure which is 760mm) Whichever liquid is lower has more pressure on it so it pushes the other side of the liquid up. Describe circular motion in terms of acceleration - CORRECT ANSWER- Because acceleration is change in velocity, an object moving in a circle is experiencing acceleration. Because the object is accelerating there is a resultant force acting upon it Describe circular motion in terms of velocity - CORRECT ANSWER- Velocity is constantly changing because direction in constantly changing. Describe how to determine the density of a liquid - CORRECT ANSWER- Measure the mass of a measuring cylinder then add the liquid to it and measure the mass taking away the mass of the measuring cylinder from the total mass. Then read the volume on the measuring cylinder and divide the mass by the volume Describe how to determine the density of a regular shaped solid - CORRECT ANSWERMeasure the mass on scales and calculate the volume (area x height) then divide mass by volume