A 74.0 kg firefighter climbs a flight of stairs 12.0 m high. How much work is required?
W = Mg
M = 74 kg
g = 9.8 m/s^2
W=Force x displacement x cos of the angle.
W=(mg)(d)(cos angle)
W=(74 x 9.8)(12)(cos 0)
W=(725.2)(12)(1)
W=8702.4 J
Ok, i was thinking the similar way but i got confused because there was no time given neither speed.
8880
To calculate the amount of work required, we can use the formula:
Work = Force x Distance x Cos(θ)
In this case, the force is equal to the weight of the firefighter, the distance is the height of the stairs, and θ is the angle between the force and the direction of motion (which is 0 degrees since the firefighter is climbing straight up).
First, let's calculate the force:
Force = Mass x Acceleration due to gravity
The mass of the firefighter is given as 74.0 kg, and the acceleration due to gravity is approximately 9.8 m/s².
Force = 74.0 kg x 9.8 m/s² = 725.2 N
Next, we can calculate the work:
Work = Force x Distance x Cos(θ)
Since cos(0 degrees) = 1, we can simplify the formula to:
Work = Force x Distance
Work = 725.2 N x 12.0 m
Work = 8702.4 Joules
Therefore, the work required to climb the flight of stairs is approximately 8702.4 Joules.