The graph below represents changes in water. What process is occurring during section “B” of the graph?

A see-saw is balanced on a pivot with two children on it. One child is sitting 1.5 m to the left of the pivot and has a mass of

Lorico [155]

Answer:

Explanation:

Remark

This is a second class lever. It is much more efficient than the fishing pole problem. All distances are measured from the pivot in these kinds of questions.

Givens

d1 = 1.5

d2 = ?

m1 = 50 kg

m2 = 30 kg

The lighter child will have to sit further away from the pivot to make the two conditions equal.

Formula

d1*m1 = d2*m2

1.5*50 = d2 * 30

75 = 30 * d2

75/30 = d2

d2 = 2.5

Remark

Notice that the distance is longer for the lighter child. The fact that these are masses and not forces does not matter, but you should take note of it. There is a difference between masses and forces. See the fishing pole problem.

Answer to the multiple Choice question. No motion on this kind of problem means equal moments. The answer is D

Problem 2

1) The wheels are further apart making B more stable. The wider the distance the wheels are apart, the harder it would be to tip the concrete mixer over

2) The center of gravity is lower. The higher the force is the more chance you have of exerting an external force to tip the mixer over.

7 0

3 years ago

What is the study of energy and how it affects matter called?

bogdanovich [222]

Physics

I hope I helped:)

6 0

3 years ago

Depending on circumstances, there are times when divers may wish to be positively, negatively or neutrally buoyant. True. False.

ser-zykov [4K]

Answer:

True

Explanation:

Buoyancy is the most important factors for divers. All they do underwater is to observe the life down there but they also have some other work. However, divers may want to be negatively buoyant when they want to go on deep exploration. When they reach a destination, they may want to observe and neutral buoyancy then will be useful. When they want to go back on surface, they’ll utilize positive buoyancy.

7 0

3 years ago

A 350-N child is in a swing that is attached to a pair of ropes 2.10 m long. Find the gravitational potential energy of the chil

o-na [289]

Answer:

a) U = 735 J , b) U = 125.7 J , c) U = 0 J

Explanation:

The gravitational power energy is

U = mg y - mg y₀

The last value is a constant, for simplicity we can make it zero, if the lowest point is at the origin of the coordinate system, which in this case we will place in the lowest part

a) Rope is horizontal

The height in this case is the same length of the rope

y = 2.10 m

w = mg = 350 N

U = 350 2.10

U = 735 J

b) when the angle is 34º

y = L - L cos 34

y = L (1- cos34)

y = 2.10 (1- cos 34)

y = 0.359 m

U = 350 0.359

U = 125.7 J

c) in this case this point coincides with the reference system

y = 0

U = 0 J

4 0

3 years ago

A solid yellow stripe is to be painted in the middle of a certain highway. If 1 gallon of paint covers an area of p square feet

marin [14]

Answer:

option A is correct

Explanation:

Given:

The length to be painted = m miles

The width to be painted = t inches

Area painted in 1 gallon = p square feet

Converting the every given dimension in feet, we have

length to be painted = m × 5280 feet

width to be painted = t/12 feet

area to be painted = (m × 5280 feet) × t/12 feet

now, applying the unitary method, we have

p square feet is painted ⇒ 1 gallon

1 square feet is painted ⇒ 1/p gallon

(m × 5280 feet) × t/12 feet square feet is painted ⇒ [(m × 5280 feet) × t/12 feet ] × 1/p gallon

thus, we get the gallons of paint required as 5820 mt/12p

hence option A is correct

3 0

3 years ago