A motorcycle is moving at a constant speed of 40km/h. How long does it take the motorcycle to travel a distance of 10km?

which element is less reactive, an element whose atoms have seven valence electrons or an element whose atoms have eight valence

Agata [3.3K]

Which element is less reactive, an element whose atoms have seven valence electrons or an element whose atoms have eight valence electrons? Why?an element with 8 valence electrons because it doesn't require any additional electrons to become stable

5 0

3 years ago

The center of gravity of an ax is on the centerline of the handle, close to the head. Assume you saw across the handle through t

andrew-mc [135]

Answer:

I believe it is they will weigh the same

Explanation:

Center of gravity is the axis on which the mass rotates evenly if I remember correctly from AP Physics

3 0

3 years ago

A speeding motorist traveling down a straight highway at 100 km/h passes a parked police car. It takes the police constable 1.0

Lubov Fominskaja [6]

Answer:

t = 7.5 s

Explanation:

The distance traveled by the car at the time of meeting of the two cars must be the same. First, we calculate the distance traveled by the police car. For that we use 2nd equation of motion. Here, we take the time when police car starts to be reference. So,

s₁ = Vi t + (0.5)gt²

where,

s₁ = distance traveled by police car

Vi = Initial Velocity = 0 m/s

t = time taken

Therefore,

s₁ = (0 m/s)(t) + (0.5)(9.8 m/s²)t²

s₁ = 4.9 t²

Now, we calculate the distance traveled by the car. For constant speed and time to be 1 second more than the police car time, due to car starting time, we get:

s₂ = Vt = V(t + 1)

where,

s₂ = distance traveled by car

V = Velocity of car = (100 km/h)(1000 m/1 km)(1 h/ 3600 s) = 27.78 m/s

Therefore,

s₂ = 27.78 t + 27.78

Now, we know that at the time of meeting:

s₁ = s₂

4.9 t² = 27.78 t + 27.78

4.9 t² - 270.78 t - 27.78 = 0

solving the equation and choosing the positive root:

t = 6.5 s

since, we want to know the time from the moment car crossed police car. Therefore, we add 1 second of starting time in this.

t = 6.5 s + 1 s

t = 7.5 s

6 0

4 years ago

A bicycle traveled 150 meters west from point A to point B. Then It took the same route and came back to point A. It took a tota

Julli [10]

Answer:

Option D. The average speed is 2.5 meters/second, and the average velocity is 0 meters/second.

Explanation:

we know that

To find out the average speed divide the total distance by the total time

Let

d -----> the total distance in meters

t -----> the time in seconds

s ----> the speed in meters per second

$s=\frac{d}{t}$

Remember that

$1\ min=60\ sec$

we have

$t=2\ min=2(60)=120\ sec$

$d=150(2)=300\ m$

substitute

$s=\frac{300}{120}$

$s=2.5\frac{m}{sec}$

Find out the average velocity

To find out the average velocity divide the displacement) by the time

The displacement is the distance from the start point to the end point regardless of the route

In this problem

The start point is A and the end point is A

so

The displacement is equal to zero

therefore

The average velocity is 0 m/sec

6 0

3 years ago

an ice cube is placed in the sun later there is a puddle of water later still the.puddle is gone what kind of change has occured

TiliK225 [7]

Clear question is;

An ice cube is placed in the sun. Later there is a puddle of water. Later still the puddle is gone. What kind of change has occurred?

Answer:

Physical change.

Explanation:

There are two type of changes called physical change and chemical change.

In Physical changes, there is only change in the appearance of the substance and not its chemical composition. Whereas, in Chemical changes the substance changes entirely into another substance with a new chemical formula.

Now, for the ice cube, it has melted from a solid state to a liquid state. Thus, there is only a change in appearance and not its chemical composition. Thus, it's a physical change that has occurred.

7 0

4 years ago