A boulder of mass 10 kg rolls over a cliff and reaches the beach below with a velocity of 15 m/s. Find:

The U. S. Navy is helping these Congolese soldiers conduct an inspection of vehicles, looking mostly for car bombs. They can ins

Mashutka [201]

A flat mirror; reflection

6 0

3 years ago

Read 2 more answers

It has been suggested that rotating cylinders about 10 mi long and 5.9 mi in diameter be placed in space and used as colonies. T

tekilochka [14]

Answer:

ω = 0.05 rad/s

Explanation:

We consider the centripetal force acting as the weight force on the surface of the cylinder. Therefore,

$Centripetal Force = Weight\\\frac{mv^{2}}{r} = mg\\\\here,\\v = linear\ speed = r\omega \\therefore,\\\frac{(r\omega)^{2}}{r} = g\\\\\omega^{2} = \frac{g}{r}\\\\\omega = \sqrt{\frac{g}{r}}\\$

where,

ω = angular velocity of cylinder = ?

g = required acceleration = 9.8 m/s²

r = radius of cylinder = diameter/2 = 5.9 mi/2 = 2.95 mi = 4023.36 m

Therefore,

$\omega = \sqrt{\frac{9.8\ m/s^{2}}{4023.36\ m}}\\\\$

7 0

3 years ago

Which of the following are true statements? A. Like charges repel B. Unlike charges repel C. Unlike charges attract or D. Charge

Brums [2.3K]

Answer: The correct answers are (A) and (C).

Explanation:

The expression from electrostatic force is as follows;

$F=\frac{kq_{1}q_{1}}{r^{2} }$

Here, F is the electrostatic force, k is constant, r is the distance between the charges and $q_{1},q_{1}$ are the charges.

The electrostatic force follows inverse square law. It is inversely proportional to the square of the distance between the charges. It is directly proportional to the product of the charges.

Like charges repel each other. There is a force of electrostatic repulsion between the like charges. Unlike charges attract each other. There is a force of electrostatic attraction between unlike charges.

The charges are induced on the neutral object when it is placed nearby the charged object without actually touching it.

Therefore, the true statements from the given options are as follows;

Like charges repel.

Unlike charges attract.

7 0

3 years ago

how much force is needed to move a brick with a mass of 345-kg a distance of 28m while doing 1008 j of work?

Travka [436]

    Work = (force) x (distance)

   1,008 J = (force) x (28 m)

Divide each side by 28m : (1,008 kg-m²/sec²) / (28 m) = force

   Force = 36 kg-m/s² = 36 Newtons .
      (about 8.1 pounds)

It doesn't matter what that force accomplishes.
It could be moving a brick, lifting a fish, or pushing a little red wagon.
In order to do 1,008 joules of work in 28 meters, it takes 36 N of force,
in the direction of the 28 meters.

5 0

3 years ago

Using a horizontal force of 60 N, a wagon is pushed horizontally across the floor a distance of 12 meters at a constant speed of

RideAnS [48]

Answer:

a) The work done by the force is 720 joules, b) The power supplied by the force is 138 watts.

Explanation:

a) Since force is uniform and parallel to the direction of motion, the work ( $W$ ), in joules, done by the force ( $F$ ), in newtons, is defined by this formula: