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3 years ago

ALWAYS use significant figure rules. Remember that these rules apply to all numbers that are measurements.

Physics

1 answer:

natali 33 [55]3 years ago

8 0

Answer:

Well I'm going to go with A.

Explanation:

As per the question the mass of the boy is 40 kg.

The boy sits on a chair.

We are asked to calculate the force exerted by the boy on the chair at sea level.

The force exerted by boy on the chair while sitting on it is nothing else except the force of gravity of earth i.e the weight of the body .The direction of that force is vertically downward.

At sea level the acceleration due to gravity g = 9.8 m/s^2

Therefore, the weight of the boy [m is the mass of the body]

we have m = 40 kg.

Therefore, w = 40 kg ×9.8 m/s^2

=392 N kg m/s^2

= 392 N

392 is not an option but I'm guessing you can round down 2 .to option A. 390...?

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Along the remote Racetrack Playa in Death valley, California, stones sometimes gouge out prominent trails in the desert floor, a

REY [17]

Answer:

F = 196 N

Explanation:

For this exercise we will use Newton's second law, we define a reference system with the x axis in the direction of movement of the stones and the y axis vertically

Y axis

N- W = 0

N = mg

X axis

F -fr = ma

In this case, they ask us for the force to keep moving, so the stones go at constant speed, which implies that the acceleration is zero.

F- fr = 0

F = fr

the friction force has the equation

fr = μ N

fr = μ mg

we substitute

F = μ mg

let's calculate

F = 0.80 9.8 25

F = 196 N

8 0

3 years ago

Object 1 has a momentum of 10 kg m/s and Object 2 has a momentum of 25 kg m/s. Will it be easier to change the direction of move

svetoff [14.1K]

Answer:

I think its object 1

Explanation:

Because the object that has more weight has a greater momentum and the lightest object that has a less momentum will be easier to change because its lighter.

5 0

3 years ago

What is the period? Blank seconds.

FromTheMoon [43]

Answer:

Period refers to the time for something to happen and is measured in seconds/cycle

8 0

3 years ago

A gas sample is confined within a chamber that has a movable piston. A small load is placed on the piston; and the system is all

timurjin [86]

Explanation:

It is given that,

Total weight of the piston, W = F = 70 N

Area of the piston, $a=5\times 10^{-4}\ m^2$

Let P is the pressure exerted on the piston by the gas. The force per unit area is called the pressure exerted pressure of the gas. Mathematically, it is given by :

$P=\dfrac{F}{A}$