A vacuum cleaner has an energy input of 6.5 kWh and an energy output of 5.8 kWh. The efficiency of the vacuum cleaner, to the nearest percentage, is

The device which is used to increase or decrease the voltage of electricity is called

When a diver gets into a tuck position by pulling in her arms and legs, she increases her angular speed. before she goes into the tuck position, her angular velocity is 5.5 rad/s and she has a moment of inertia of 2.0 kg · m2.

A net force of 2455N accelerates a car from rest to 10.70m/s in 7.0s. what is mass of the car?

How does the equivalent resistance of a series circuit compare to the resistance value of the individual resistance in the circuit?

For which pair of launch angles will two identical projectiles have equal ranges?. A. 19.24°, 80.54°B. 16.42°, 74.58°C. 60.23°, 29.77°D. 89.53°, 01.47°E. 42.42°, 47.59°

What does the speed of sound depend on? A. Medium that the sound travels through B. Acoustics C. Frequency of the sound D. Loudness of the sound

Which of these is not a source of the shock waves that lead to protostars?

Which kind of information is known about a person if that person's DNA is in a database? A. how old the person is B. where the person was probably born C. some diseases the person might have D. whether the person is likely to commit a crime

A science teacher ran a marathon. After the race she showed her students the silver blanket she was given to keep her warm. A group of students investigated how the colour of the blanket affected how much infrared radiation is absorbed

Students asked to measure the temperature of a reaction beaker recorded the following temperatures. 103.7°C, 108.4°C, 105.8°C, 104.6°C The actual temperature is 105.1°C. Which measurement is the most precise