Which one is not a derived unit? 1. Hertz 2. mol 3. Watt 4. Newton

A 15 m ladder with a mass of 51 kg is leaning against a frictionless wall, which makes an angle of 60 degrees with the horizonta

timofeeve [1]

Answer:

Explanation:

Given that, .

Mass of ladder is 51kg

Then, it weight is

WL = mg = 51 × 9.81 = 500.31N

This weight will act at the midpoint of the ladder

Length of ladder is 15m

The ladder makes an angle 55°C with the horizontal

An object whose mass is 81kg is at 4m from the bottom of the ladder

Then, weight of object

Wo = mg = 81 × 9.81 = 794.61 N

Using newton second law

Check attachment

Ng is normal force on the ground

Ff is the horizontal frictional force

Nw Is the normal force on the wall

ΣFy = 0

Ng = Wo + WL

Ng = 794.61 + 500.31

Ng = 1294.92 N

Also

ΣFx = 0

Ff — Nw = 0

Then,

Ff = Nw

Now taking moment about point A.

Check attachment

using the principle of equilibrium

Sum of clockwise moment equals to sum of anti-clockwise moment

Also note that the Normal force on the wall is not perpendicular to the ladder, so we will resolve that and also the weights of ladder and weight of object

Clockwise = Anticlockwise

Wo•Cos60 × 4 + WL•Cos60 × 7.5 = Nw•Sin60 × 15

794.61Cos60 × 4 + 500.31Cos60 × 7.5 = Nw × Sin60 × 15

1589.22 + 1876.163 = 12.99•Nw

3465.383 = 12.99•Nw

Nw = 3465.383 / 12.99

Nw = 266.77 N

Since, Nw = Ff

Then, Ff = 266.77N

the horizontal force exerted by the ground on the ladder is 266.77 N

8 0

3 years ago

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A sound wave has a frequency of 300 Hz. If the wavelength is .50 m, then what is the speed of

kherson [118]

Answer:

15000 m/s

Explanation:

You just need to multiply the wavelength with the frequency.

7 0

2 years ago

A 65kg person throw a 0.045kg snowball forward with a ground speed of 30m/s. A second person, with a mass of 60kg, catches the s

Kobotan [32]

Well, st first we should find initial momentum for the first person represented in the task which definitely must be :
 $(65+0.045)*2.5$
And then we find the final one : $65*x + 0.045*30$
Then equate them together : $x=2.48 m/s$
So we can get the velocity, which is $is 2.48 m/s$
In that way, according to the main rules of conservation of momentum you can easily find the solution for the second person.
Regards!

6 0

3 years ago

When a car driving up a hill with constant speed: I. its kinetic energy is decreasing. II. its potential energy is constant. III

madam [21]

A car driving up a hill at a constant speed experiences no change in its kinetic energy while it's potential energy increases with increasing height, thus none of the options are correct.

Understanding the concept

Consider a car moving up the hill at a constant speed as shown in the figure below. The following forces act on the car:

N is the normal reaction force acting in an upward direction

f_s is the static friction force exerted due to friction between the road and the tires of the car
f_k is the rolling friction force in the direction opposing that of the tire
mg is the force acting in a downward direction.

θ is the angle of inclination.

Here as the car is moving up the hill at a constant speed, the net force exerted on the car is zero. Also, the kinetic energy of the car will not change as its velocity is constant and the potential energy will change with increasing height. Thus, none of the given options are correct.

Learn more about motion on an incline here:

brainly.com/question/13513083

#SPJ4

5 0

1 year ago

The main part of the nuclear power plant is the ____. Where nuclear ____ reactions take place.

emmasim [6.3K]

Turbine an unclean fission

7 0

3 years ago

Read 2 more answers

Which one is not a derived unit?1. Hertz2. mol3. Watt4. Newton​

Which one is not a derived unit?1. Hertz2. mol3. Watt4. Newton