If the tension of the cable is 25.0 N what is the mass of the ball

At the local playground, a 21-kg child sits on the right end of a horizontal teeter-totter, 1.8 m from the pivot point. On the l

Ksju [112]

Answer:

By convention a negative torque leads to clockwise rotation and a positive torque leads to counterclockwise rotation.

here weight of the child =21kgx9.8m/s2 = 205.8N

the torque exerted by the child Tc = - (1.8)(205.8) = -370.44N-m ,negative sign is inserted because this torque is clockwise and is therefore negative by convention.

torque exerted by adult Ta = 3(151) = 453N , counterclockwise torque.

net torque Tnet = -370.44+453 =82.56N , which is positive means counterclockwise rotation.

b) Ta = 2.5x151 = 377.5N-m

Tnet = -370.44+377.5 = 7.06N-m , positive ,counterclockwise rotation.

c)Ta = 2x151 = 302N-m

Tnet = -370.44+302 = -68.44N-m, negative,clockwise rotation.

5 0

3 years ago

find the average velocity of a bicycle that starts 100km south and is 120km south of town after 0.4 hours

dusya [7]

Answer:

The average velocity is 50 km/h south

Explanation:

The average velocity of an object is its total displacement divided by

the total time taken.

That means it is the rate at which an object changes its position from

one place to another.

Average velocity is a vector quantity.

The SI unit is meters per second.

A bicycle that starts 100 km south and is 120 km south of town after

0.4 hour.

The displacement = 120 - 100 = 20 km south

The time = 0.4 hour

The average velocity = $\frac{D}{T}$ , where D is the displacement

and t is the time

The average velocity of the bicycle = $\frac{20}{0.4}=50$ km/h

<em>The average velocity is 50 km/h south</em>

If you want it in meter per second, change the kilometer to meter

and change the hour to seconds

1 km = 1000 m

1 hour = 60 × 60 = 3600 seconds

The average velocity of the bicycle = $\frac{50(1000)}{3600}=13.89$ m/s south

5 0

2 years ago

Give me three examples of fossil fuel-based energy sources pls

svet-max [94.6K]

Gasoline, kerosene, and coal.

4 0

3 years ago

A man has a mass of 66 kg on earth. What’s his weight in pounds?

Vlad1618 [11]

Answer:

646.8 N

Explanation:

3 0

2 years ago

What is the conductor's resistance if its length is 2m and has a cross-sectional area of 0.7m with a resistivity of4Ωm? a. 1.4 Ω

Firlakuza [10]

Answer:

The answer is c. 11.42 Ohm

Explanation:

The conductor's resistance is calculated by the formula in the figure.

So, you have to replace the given values into the formula.

Resistance of a conductor is equal to the product of rho by the lengh of the conductor divided the cross-sectional area of the conductor.

$R= 4 ohm.m . (2m/o.7m^{2} )\\R=11.42ohm$

3 0

3 years ago