1. POWER THE RATE AT WHICH WORK IS BEING DONE

2. POWER THE RATE OF DOING WORK WORK = FORCE * DISTANCE IS SO WHAT IS THE UNIT FOR POWER?

3. Joules/sec or Watts 1 watt is the power produced by a force of 1N moving an object 1ms -1

4. CALCULATE & COMPARE POWER DURING THE ASCENT PHASE OF A REP OF THE BENCH PRESS, TWO LIFTERS EACH EXERT AN AVERAGE VERTICAL FORCE OF 1000 N AGAINST A BARBELL WHILE THE BARBELL MOVES 0.8 M UPWARD. BUT EACH TAKES A DIFFERENT AMOUNT OF TIME. CALCULATE THE POWER OF EACH. LIFTER A: 0.50 SECONDS LIFTER B: 0.75 SECONDS

5. CALCULATE & COMPARE POWER LIFTER A TABLE OF VARIABLES F = 1000 N D = 0.8 M T = 0.50 S LIFTER B TABLE OF VARIABLES F = 1000 N D = 0.8 M T = 0.75 S

6. POWER ON A STATIONARY BIKE GIVEN A FORCE OF 3N AND DISPLACEMENT OF 6M PER REVOLUTION, WHAT IS THE POWER PER MINUTE IF A REVOLUTION TAKES 1 SEC?

7. RUNNING UP STAIRS DURING THE POWERHOUSE LAB, JEROME RUNS UP THE STAIRS, ELEVATING HIS 102 KG BODY A VERTICAL DISTANCE OF 2.29 METERS IN A TIME OF 1.32 SECONDS AT A CONSTANT SPEED. A. DETERMINE THE WORK DONE BY JEROME IN CLIMBING THE STAIR CASE. B. DETERMINE THE POWER GENERATED BY JEROME.

8. RUNNING UP STAIRS DURING THE POWERHOUSE LAB, JEROME RUNS UP THE STAIRS, ELEVATING HIS 102 KG BODY A VERTICAL DISTANCE OF 2.29 METERS IN A TIME OF 1.32 SECONDS AT A CONSTANT SPEED. A. W = 102 * 10 * 2.29 = 2335.8J B. 2335.8 / 1.32 = 1769.5W

9. THE SKI SLOPES AT BLUEBIRD MOUNTAIN MAKE USE OF TOW ROPES TO TRANSPORT SNOWBOARDERS AND SKIERS TO THE SUMMIT OF THE HILL. ONE OF THE TOW ROPES IS POWERED BY A 22-KW MOTOR WHICH PULLS SKIERS ALONG AN ICY INCLINE OF 14° AT A CONSTANT SPEED. SUPPOSE THAT 18 SKIERS WITH AN AVERAGE MASS OF 48 KG HOLD ONTO THE ROPE AND SUPPOSE THAT THE MOTOR OPERATES AT FULL POWER. A. DETERMINE THE CUMULATIVE WEIGHT OF ALL THESE SKIERS. B. DETERMINE THE FORCE REQUIRED TO PULL THIS AMOUNT OF WEIGHT UP A 14° INCLINE AT A CONSTANT SPEED. C. DETERMINE THE SPEED AT WHICH THE SKIERS WILL ASCEND THE HILL.

10. THE SKI SLOPES AT BLUEBIRD MOUNTAIN MAKE USE OF TOW ROPES TO TRANSPORT SNOWBOARDERS AND SKIERS TO THE SUMMIT OF THE HILL. ONE OF THE TOW ROPES IS POWERED BY A 22-KW MOTOR WHICH PULLS SKIERS ALONG AN ICY INCLINE OF 14° AT A CONSTANT SPEED. SUPPOSE THAT 18 SKIERS WITH AN AVERAGE MASS OF 48 KG HOLD ONTO THE ROPE AND SUPPOSE THAT THE MOTOR OPERATES AT FULL POWER. A. DETERMINE THE CUMULATIVE WEIGHT OF ALL THESE SKIERS. B. DETERMINE THE FORCE REQUIRED TO PULL THIS AMOUNT OF WEIGHT UP A 14° INCLINE AT A CONSTANT SPEED. C. DETERMINE THE SPEED AT WHICH THE SKIERS WILL ASCEND THE HILL. a.Weight = 48*18*10*cos(14) = 8383N b.Force = 8383 * sin(14) = 2028N c.22000 = 2028 * v v = 22000/2028 = 10.8ms -1