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Dennis_Churaev [7]

3 years ago

9

You carry a 7.0 kg bag of groceries above the level floor at a constant velocity of 75 cm/s across a room that is room. How much

work do you do on the bag in the process?

1 answer:

VARVARA [1.3K]3 years ago

7 0

Answer:

1.97J

Explanation:

Given parameters:

Mass of the groceries = 7kg

velocity of the bag = 75cm/s

Unknown:

Work done to move the bag = ?

Solution:

Work done is the force applied to move a body through a distance in a specific direction:

Work done = Force x distance

In this case, the work done is the kinetic energy applied in pulling the bag.

Kinetic energy is the energy in motion of a body.

Work done = kinetic energy = $\frac{1}{2} m v^{2}$

where m is the mass

v is the velocity

Now, convert the velocity from cm/s to m/s

100cm = 1m

75 $\frac{cm}{s }$ x $\frac{1m}{100cm}$ = 0.75m/s

Work done = $\frac{1}{2}$ x 7 x 0.75² = 1.97J

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