1.) How much energy does a 60 W light bulb consume in 1 hour?
2.) Beth pulled her brother (m=85 kg) in a 10 kg sled with a constant force of 95 N for 100 m.
a) How much work did Beth do in moving her brother?
b) How much power did she expend if it took her 3 min (180 s) to move this distance?
energy=power*timeinSeconds
Beth
a. force*distance=work
b. power=work/time
1.) To calculate the energy consumed by a light bulb, you need to multiply the power (in watts) by the time (in hours). In this case, the power of the light bulb is given as 60 W, and the time is 1 hour.
Energy = Power × Time
Substituting the given values into the equation:
Energy = 60 W × 1 hour
Since the time is given in hours, there's no need for conversion.
Therefore, the light bulb consumes 60 watt-hours (Wh) of energy in 1 hour.
2.) To calculate the work done by Beth in pulling her brother on the sled, you need to multiply the force (in newtons) by the distance (in meters). The force is given as 95 N, and the distance is given as 100 m.
a) Work = Force × Distance
Substituting the given values into the equation:
Work = 95 N × 100 m
Therefore, Beth did 9500 joules (J) of work in moving her brother.
b) Power is the rate at which work is done. To calculate power, divide the work done by the time taken. The work is given as 9500 J, and the time is given as 180 seconds.
Power = Work / Time
Substituting the given values into the equation:
Power = 9500 J / 180 s
To convert seconds to minutes, divide by 60:
Power = 9500 J / (180 s/60)
Simplifying:
Power = 9500 J / 3 min
Therefore, Beth expended 3166.67 watts (or 3.17 kW) of power in moving her brother.