Samostoiatelnaia Rabota 10 Srednii Uroven Fizika 7 Klass Direct

To lift the object, the force applied must equal the weight of the object (

P=300 N⋅25 m/s=7500 W (or 7.5 kW)cap P equals 300 N center dot 25 m/s equals 7500 W (or 7.5 kW) Quick Check Table samostoiatelnaia rabota 10 srednii uroven fizika 7 klass

A=80 N⋅1.2 m=96 Jcap A equals 80 N center dot 1.2 m equals 96 J 2. Calculating Power from a Well A person lifts a bucket of water with a mass of deep well in . What power do they develop? Identify Knowns: Calculate Work First: First, find the force ( ).Then, find work ( Calculate Power: Using To lift the object, the force applied must

P=1200 J15 s=80 Wcap P equals the fraction with numerator 1200 J and denominator 15 s end-fraction equals 80 W 3. Power of a Moving Vehicle A motorboat develops a pulling force of while moving at a speed of . Find the engine's power. Convert Speed to SI Units: Identify Knowns: Calculate Work First: First, find the

v=90 km/h=90000 m3600 s=25 m/sv equals 90 km/h equals the fraction with numerator 90000 m and denominator 3600 s end-fraction equals 25 m/s Since , we can use Calculate Power:

F=8 kg⋅10 N/kg=80 Ncap F equals 8 kg center dot 10 N/kg equals 80 N Using