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3 years ago

8

A 25 kg rock resting on the bottom of a lake must be moved from the paths of boats. The rock has a density of 2350 kg/m^3. What

force is needed to lift the rock while under water?

1 answer:

algol133 years ago

7 0

Answer:

The force needed is the weight of the rock minus the buoyant force.

Explanation:

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How might you describe the mathematical procedure of finding the displacement when an object travels in two opposite directions?

levacccp [35]

Displacement is a vector quantity. So, you incorporate the vector calculations when you try to determine the resultant vector. This is the shortest path from the starting point to the endpoint. If they are moving on one axis only, you use sign conventions. For motions moving to the left, use the negative sign. If it's moving to the right, then use the positive sign. Now, it the object moves 2 km to the left, and 2 km also to the right, the displacement is zero.

Displacement = 2 km - 2km = 0

Generally, the equation is:
<span>Displacement = Distance of motion to the right - Distance of motion to the left</span>

4 0

3 years ago

6. Two light bulbs are designed for use at 120 V and are rated at 75 W and 150 W. Which light bulb has the greater filament resi

Nonamiya [84]

$\\ \bull\tt\longrightarrow P=\dfrac{V^2}{R}$

P is power
R is resistance

$\\ \bull\tt\longrightarrow R=\dfrac{V^2}{P}$

Hence

$\\ \bull\tt\longrightarrow R\propto V$

$\\ \bull\tt\longrightarrow R\propto \dfrac{1}{P}$

Therefore if power is low then resistance will be high.

The first bulb has less power hence it has greater filament resistance.

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2 years ago

A chef places an open sack of flour on a kitchen scale. The scale reading of

Novay_Z [31]

Answer:

Explanation:

Given

Initial reading on scale =40 N

So, we can conclude that weight of the sack is 40 N

After this a 10 N force is applied upward on the sack such that the net force becomes (40-10) N downward (because downward force is more)

This net downward force is the resultant of earth graviational pull and the applied upward force.

So, this downward force acts on the machine which inturn applies an upaward force of same magnitude called Normal reaction.

This situation can be diagramatically represented by figure given below

4 0

3 years ago

Plz answer this very soon

tester [92]

Answer:

Im gonna say it is answer A:) Hope this helps!

Explanation:

6 0

3 years ago

Read 2 more answers

Your friend says an appliance uses energy. How would you correct his statement?

madreJ [45]

Answer:

Not all appliances run on energy. Some of them run on gas. Some both. It just depends on the age of the appliance, the make of the appliance, and the company who made it.

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2 years ago