A 855 N crate rests on the floor.
a) How much work is required to move it at constant speed 7.7 m along the floor against a friction force of 180 N?
b) How much work is required to move it at constant speed 7.7 m vertically?
I really NEED help I am very lost with physics!!!!
7.7 is the height in this problem not the speed.
I figured A out it was 1386 J, but I can not figure out B I used 855X9.8x7.7 and that's not right can you tell me where I went wrong?
I'm here to help you with your physics questions! Don't worry, I'll explain everything step by step so that you can understand how to approach these problems.
a) To determine the amount of work required to move the crate along the floor against the friction force, we need to calculate the work done against friction.
Work can be calculated using the formula:
Work = Force × Distance × cos(θ)
In this case, the force is the friction force of 180 N, the distance is 7.7 m, and θ is the angle between the applied force and the displacement. Since the crate is being moved along the floor, the angle θ is 0 degrees (cos(0) = 1).
Therefore, the work done against friction is:
Work = 180 N × 7.7 m × cos(0)
Work = 180 N × 7.7 m × 1
Work = 1386 N·m
Work = 1386 Joules
So, the amount of work required to move the crate along the floor against the friction force is 1386 Joules.
b) To determine the amount of work required to move the crate vertically, we need to consider the gravitational force acting on the crate.
The work done against gravity can be calculated using the formula:
Work = Force × Distance × cos(θ)
In this case, the force is the weight of the crate, which is given as 855 N. The distance is 7.7 m, and θ is the angle between the applied force and the displacement. Since the crate is being moved vertically, the angle θ is 180 degrees (cos(180) = -1).
Therefore, the work done against gravity is:
Work = 855 N × 7.7 m × cos(180)
Work = 855 N × 7.7 m × -1
Work = -6541.5 N·m
Work = -6541.5 Joules
Note that the negative sign indicates that work is done against gravity.
So, the amount of work required to move the crate vertically is -6541.5 Joules.
I hope this helps! Let me know if you have any further questions.
well, there is no answer for b, unless you know the height. As height changes, gravitational potenial energy changes, so you had to put more energy in. IF this is all there is to the problem, you cannot do it, the problem is deficient. 7.7 is the speed. you cannot get height frm speed without time...however, you can get the POWER in watts used (Power=work/time)
Power= m*g*speed
and
work= Power*time but you have to have again height to get the time.
a) work= force applied*distance
and force applied has to equal friction.
b) work=increase in gravitational PE
= mass*g*height
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