A 4.00kg crate is slowly lifted to a height of 1.50 m.(a)How much work is done by the lifting force? (b)against gravity? (c)by gravity?
Force = mass*acceleration
Here the acceleration is from gravity.
Work=Force*distance.
(a). 58.8joules
(b).0joules
(a) To find the work done by the lifting force, we need to determine the force exerted by the lifting force. Since the crate is slowly lifted, it means that the force exerted by the lifting force is equal in magnitude but opposite in direction to the force exerted by gravity. Therefore, the force exerted by the lifting force is equal to the weight of the crate, which can be calculated using the formula:
Force = mass * acceleration
Since the acceleration here is due to gravity and is approximately 9.8 m/s^2, we can calculate the force exerted by the lifting force as follows:
Force = 4.00 kg * 9.8 m/s^2
Force = 39.2 N
Now that we have found the force exerted by the lifting force, we can calculate the work done by the lifting force using the formula:
Work = Force * distance
Given that the height is lifted is 1.50 m, we can calculate the work as follows:
Work = 39.2 N * 1.50 m
Work = 58.8 joules
Therefore, the work done by the lifting force is 58.8 joules.
(b) To find the work done against gravity, we can use the same formula as above:
Work = Force * distance
Since the force exerted by gravity is equal in magnitude but opposite in direction to the lifting force, the work done against gravity will be the negative of the work done by the lifting force. Therefore, the work done against gravity is -58.8 joules.
(c) To find the work done by gravity, we can use the same formula as above:
Work = Force * distance
Since gravity is doing work on the crate as it is being lifted, the work done by gravity will be equal in magnitude but opposite in sign to the work done by the lifting force. Therefore, the work done by gravity is also -58.8 joules.