Question

A 500 kg rock has fallen in the middle of the road.

It is necessary to move it 10 meters to let the passage of the
cars. We will use a power excavator of
3.25 kW. How long will it take the excavator to
remove the rock?

Answer 1

To calculate the time it will take the excavator to remove the rock, we need to use the formula: Time = Work / Power. The force applied is equal to the weight of the rock, which is given by the formula: Force = mass x acceleration due to gravity.

Step-by-step explanation:

To calculate the time it will take the excavator to remove the rock, we need to use the formula: Time = Work / Power First, let's calculate the work done by the excavator. Work is equal to the force applied multiplied by the distance moved. The force applied is equal to the weight of the rock, which is given by the formula: Force = mass x acceleration due to gravity The acceleration due to gravity is approximately 9.8 m/s^2. Therefore, the force applied is: Force = 500 kg x 9.8 m/s^2 = 4900 N Next, we can calculate the work done: Work = Force x Distance Work = 4900 N x 10 m = 49000 N.m Now, we can substitute the values into the formula to find the time: Time = Work / Power Time = 49000 N.m / 3250 W = 15.08 seconds Therefore, it will take the excavator approximately 15.08 seconds to remove the rock.