1. What affects a material's resistance?

A 75.0-kg painter climbs a ladder that is 2.75 m long leaning against a vertical wall. The ladder makes a 30.0° angle with the w

Schach [20]

<h3><u>Answer;</u></h3>

a) 178.6125 Joules

b) Work done does not depend on constant speed or acceleration up the ladder

<h3><u>Explanation</u>;</h3>

Work done =Fd times the cosine of angle between;

where F is force d is distance m is the mass a is acceleration

.F=ma. In this case a=g=9.81 m/s^2 and cos 30=0.866

Therefore;

W= 75 × 9.81 × 2.75 × .866

= 178.6125 Joules

b. The work done by the painter does not depend on whether the painter climbs at constant speed or accelerates up the ladder.

W=3376.945 Joules

6 0

3 years ago

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The eagle drops the trout a height of 6.1 m the fish travels 7.9 m horizontaly before hitting the water what is the velocity of

Semenov [28]

The velocity of the eagle is 7.0 m/s

Explanation:

The motion of the fish is a projectile motion, which consists of two independent motions:

- A uniform motion (constant velocity) along the horizontal direction, where the horizontal velocity of the fish is equal to the horizontal velocity of the eagle

- An accelerated motion with constant acceleration (acceleration of gravity) in the vertical direction

We start by analyzing the vertical motion, using the following suvat equation:

$s=ut+\frac{1}{2}at^2$

where:

s = 6.1 m is the vertical displacement of the fish

u = 0 is the initial vertical velocity of the fish

$a=g=9.8 m/s^2$ is the acceleration of gravity

t is the time

Solving for t, we find the time of flight of the fish:

$t=\sqrt{\frac{2s}{a}}=\sqrt{\frac{2(6.1)}{9.8}}=1.12 s$

Now we know that during this time, the fish travels a horizontal distance of

x = 7.9 m

Therefore, the horizontal velocity of the fish is

$v_x = \frac{x}{t}=\frac{7.9}{1.12}=7.0 m/s$

And therefore, this is the initial velocity of the eagle.

Learn more about projectile motion:

brainly.com/question/8751410

#LearnwithBrainly

6 0

4 years ago

Explain the process of why the balloon is attracted to the wall, and why electrons are not transferred in this process. Is the w

strojnjashka [21]

Answer:

The process by which the balloon is attracted and possibly sticks to the wall is known as static electricity which is the attraction or repulsion between electric charges which are not free to move.

The wall is an insulator.

Explanation:

When a balloon is blown and tied off, and then the balloon is rubbed on the woolly object once in one direction, and the side that was rubbed against the wool is brought near a wall and then released, it is observed that the balloon is attracted to and sticks to the wall. The above observation is due to static electricity.

Static electricity refers to electric charges that are not free to move or that are static. One of the means of generating such charges is by friction. When the balloon is rubbed on the woollen material, electrons are given away to the balloon's surface. Since the balloon is an insulator (materials which do not allow electricity to pass through them easily), the electrons are not free to move. When the balloon is brought near to a wall, there is a rearrangement of the charges present on the wall. Negative charges on the wall move farther away while the positive charges on the wall are attracted to the electrons on the balloon's surface. Because the wall is also an insulator, the charges are not discharged immediately. Therefore, this attraction between opposite charges as well as the static nature of the charges results in the balloon sticking to the wall.

6 0

3 years ago

When a 2.40-kg object is hung vertically on a certain light spring described by Hooke's law, the spring stretches 2.92 cm.(a) Wh

Anastasy [175]

Answer:

805.48N/m

Explanation:

According to Hookes law

F = Ke

F is the force = mg

F = 2.4×9.8 = 23.52N

e is the extension = 2.92cm = 0.0292m

Force constant K = F/e

K = 23.52/0.0292

K = 805.48N/m

Hence the force constant of the spring is 805.48N/m

3 0

3 years ago

Suppose you have two magnets. Magnet A doesn't have its poles labeled, but Magnet B does have a clearly labeled north and south

Elina [12.6K]

Before going to answer this question first we have to know the fundamental principle of magnetism.

A magnet have two poles .The important characteristic of a magnet is that like poles will repel each other while unlike poles will attract each other.

Through this concept the question can be answered as explained below-

A-As per first option the side of magnet A is repelled by the south pole of magnet B. Hence the pole of a must be south .It can't be north as it will lead to attraction.

B-The side of magnet A is repelled by the north pole of magnet B. Hence the side of A must be north pole.It can't be a south pole.

C-The side of magnet A is attracted by the south pole of magnet B .Hence the side of magnet A must be north.Hence this is right

D-The side of magnet A is attracted by the north pole of magnet B. Hence the side of A must south.It can't be north as it will lead to repulsion.

Hence the option C is right.

3 0

3 years ago

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