12. The diameter of a circle is 2.42m. Calculate itsarea in proper significant figure

Physics

1 answer:

Sever21 [200]3 years ago

7 0

Answer:

A = 4.6 [m²]

Explanation:

The area of a circle can be calculated by means of the following equation.

$A=\frac{\pi }{4} *D^{2}$

where:

A = area [m²]

D = diameter = 2.42 [m]

Now replacing:

$A=\frac{\pi }{4} *(2.42)^{2} \\A = 4.6 [m^{2} ]$

You might be interested in

If a team of workers comes to a consensus, what probably happened in the meeting?

Feliz [49]

Answer:

Explanation:

A consensus is when you come to an agreement

7 0

3 years ago

A force of 30n is applied to a screwdriver to pry the lid off of a can of paint. The screwdriver applies 75n of force to the lid

gizmo_the_mogwai [7]

The mechanical advantage of the screwdriver that is being described above is equal to 75N. This means that for every 30N that is applied on the screwdriver, this simple machine would in turn apply 75N of force to the lid of the can.

3 0

3 years ago

You are performing a knee extension exercise. You hold a 20kg weight at full knee extension. The weight is 0.4m from your knee j

dmitriy555 [2]

Answer:

The moment is -78.4 N-m (clockwise).

Explanation:

Given:

Mass of the object (m) = 20 kg

Distance of the object from the knee joint (d) = 0.4 m

Weight of leg is not considered.

Acceleration due to gravity (g) = 9.8 m/s²

Now, weight of the object is equal to the product of its mass and acceleration due to gravity. So,

Weight = Mass × Acceleration due to gravity

= $mg=20\times 9.8 =196\ N$

We know that, moment of a force about a point is defined as the product of force applied and the perpendicular distance between the point and the line of application of force.

Moment of the given weight about the knee joint is given as:

Moment about knee joint = Weight × Distance from knee joint to weight

Moment about knee joint = 196 × 0.4 = 78.4 Nm

Now, from the diagram below, we can observe that, the weight acts vertically down and thus the sense of rotation about the knee joint at point O is clockwise. So, moment is negative.

Therefore, the moment is -78.4 N-m (clockwise).