A 80 kg firefighter climbs flight of stairs 6 meter high in 10 seconds.
How much work is required by the firefighter?
Work = F*d = Mg*d = 80*9.8 * 6 = 4704 J
A dog does 12'500 I of work when he pulls a wagon that weighs 250 N. How far did the dog pull the wagon
Well, I don't want to burst your bubble, but I'm not sure the firefighter had time to calculate that while climbing the stairs. However, I'm happy to crunch the numbers for you! To calculate the work done, we can use the formula: work = force x distance. The force exerted by the firefighter can be calculated using their weight, which is mass x gravity. So, force = 80 kg x 9.8 m/s^2 (acceleration due to gravity) = 784 N. Now, we can calculate the work done: work = force x distance = 784 N x 6 m = 4704 Joules. That's a whole lot of work!
To calculate the work required by the firefighter, we can use the formula:
Work (W) = Force (F) × Distance (d) × Cosine of angle (θ)
Given that the firefighter is climbing a flight of stairs, we can assume the angle of ascent is 0 degrees. In this case, the cosine of 0 degrees is 1, so we can simplify the equation to:
Work (W) = Force (F) × Distance (d)
Now, to find the force exerted by the firefighter, we can use Newton's second law of motion, which states that force is equal to mass (m) multiplied by acceleration (a). Since the firefighter is climbing the stairs with a constant velocity, the acceleration is 0.
Therefore, the equation becomes:
Force (F) = mass (m) × acceleration (a)
= 80 kg × 0 m/s²
= 0 N
Now we can substitute the values into the work equation:
Work (W) = 0 N × 6 m
= 0 J
Hence, no work is required by the firefighter as the force exerted is 0.
To calculate the work required by the firefighter, we can use the formula:
Work = Force × Distance × Cos(theta)
Where:
- Force is the force applied by the firefighter while climbing the stairs.
- Distance is the vertical distance the firefighter climbs.
- Theta is the angle between the force and the direction of motion (which is 0 degrees in this case, as the firefighter is climbing straight up).
In this scenario, we need to find the force applied by the firefighter. We can find it using Newton's second law of motion, which states:
Force = Mass × Acceleration
In this case, the acceleration can be calculated using the formula:
Acceleration = Change in velocity ÷ Time
Given that the firefighter climbs a flight of stairs 6 meters high in 10 seconds, we can calculate the acceleration as follows:
Acceleration = (Change in velocity) ÷ Time = (0 m/s - 0 m/s) ÷ 10 s = 0 m/s²
Since there is no change in velocity (the firefighter starts and finishes at rest), the acceleration is 0 m/s².
Now, we can calculate the force applied by the firefighter:
Force = Mass × Acceleration = 80 kg × 0 m/s² = 0 N
Finally, we can calculate the work done by the firefighter using the work formula mentioned earlier:
Work = Force × Distance × Cos(theta) = 0 N × 6 m × Cos(0) = 0 J
Therefore, the amount of work required by the firefighter is 0 joules.