A train travels 100 km east and then 75 km west. What is the magnitude of its displacement?

Protons have a positive charge A.True B.False

PIT_PIT [208]

Answer:

TRUE

Explanation:

Protons have a positive charge. Electrons have a negative charge. The charge on the proton and electron are exactly the same size but opposite. Neutrons have no charge.

5 0

3 years ago

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Which of the following material offers the lowest resistivity?

Yuki888 [10]

Lower resistivity means higher conductivity: among these materials, the best conductor is silver, therefore it must be the material with lowest resistivity among those. We can also have a look at the value of resistivity of the different materials listed in the problem, to check our answer. The resistivities of the materials are the following:
Wood: $1.00\cdot 10^{3} \Omega \cdot m$
Salt water: $2.00\cdot 10^{-1} \Omega \cdot m$
Silver: $1.59\cdot 10^{-8} \Omega \cdot m$
Lead: $2.20\cdot 10^{-7} \Omega \cdot m$
We see that the material with lowest resistivity among those is silver, therefore the correct answer is silver.

7 0

2 years ago

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A vector A has a magnitude of 5 units and points in the −y-direction, while a vector B has triple the magnitude of A and points

Harman [31]

Answer:

A+B; 5√5 units, 341.57°

A-B; 5√5 units, 198.43°

B-A; 5√5 units, 18.43°

Explanation:

Given A = 5 units

By vector notation and the axis of A, it is represented as -5j

B = 3 × 5 = 15 units

Using the vector notations and the axis, B is +15i. The following vectors ate taking as the coordinates of A and B

(a) A + B = -5j + 15i

A+B = 15i -5j

|A+B| = √(15)²+(5)²

= 5√5 units

∆ = arctan(5/15) = 18.43°

The angle ∆ is generally used in the diagrams

∆= 18.43°

The direction of A+B is 341.57° based in the condition given (see attachment for diagrams

(b) A - B = -5j -15i

A-B = -15i -5j

|A-B|= √(15)²+(-5)²

|A-B| = √125

|A-B| = 5√5 units

The direction is 180+18.43°= 198.43°

See attachment for diagrams

(c) B-A = 15i -( -5j) = 15i + 5j

|B-A| = 5√5 units

The direction is 18.43°

See attachment for diagram

5 0

3 years ago

Lana wanted to do an investigation to see what kind of birdseed the birds in her neighborhood like best. She purchased three of

Misha Larkins [42]

Answer:

The level of seed in each feeder

Explanation:

The independent variable is the variable which is the suspected cause of an observation, it is the variable that produce the effect observed in the dependent variable. The dependent variable is the variable that is measured

The independent variable is normally the x-value while the dependent variable is the y-value

In the question, Lana wants to find out the kind of birdseed that the neighborhood birds like (to eat) the most by feeding them different types of birdseed and measuring the level of the birdseed in the feeders at regular intervals

the independent variable is the bird seed types which Lana gives to the birds, to determine the type of bird seeds the birds like

The dependent variable is the level of the seed in the feeder which depends on the type of seeds the birds like.

3 0

3 years ago

A large truck is moving 22.0 m/s. If it’s momentum is 125,000 kg • m/s, what is the trucks mass

strojnjashka [21]

Answer:

p = mv

m = p/v = 125000/22 = 5682 kg

Explanation:

Direct application of the momentum equation

p = mv

where,

p: momentum

m: mass

v: object velocity

steps:

-------

1) check for units consistency ( SI or Imperial)

2) separate the variable you are looking for.

3) DONE! :DD

6 0

2 years ago