_______________have a negative charge and are located on the outside of the nucleus.

A net force of 15 N is exerted on an encyclopedia to cause it to accelerate at a rate of 5 m/s2. Determine the mass of the encyc

lina2011 [118]

Answer:

Explanation:

The mass of the encyclopedia can be found by using the formula

$m = \frac{f}{a} \\$

f is the force

a is the acceleration

From the question we have

$m = \frac{15}{5} \\$

We have the final answer as

Hope this helps you

6 0

2 years ago

PLEASE help me with this science question.

frez [133]

What’s the question

7 0

2 years ago

Read 2 more answers

HELP ASAP!!!

miss Akunina [59]

Write each force in component form:

v ₁ : 50 N due east → (50 N) i

v ₂ : 80 N at N 45° E → (80 N) (cos(45°) i + sin(45°) j ) ≈ (56.5 N) (i + j )

The resultant force is the sum of these two vectors:

r = v ₁ + v ₂ ≈ (106.5 N) i + (56.5 N) j

Its magnitude is

|| r || = √[(106.5 N)² + (56.5 N)²] ≈ 121 N

and has direction θ such that

tan(θ) = (56.5 N) / (106.5 N) → θ ≈ 28.0°

i.e. a direction of about E 28.0° N. (Just to clear up any confusion, I mean 28.0° north of east, or 28.0° relative to the positive x-axis.)

4 0

2 years ago

A catapult launches a test rocket vertically upward from a well, giving the rocket an initial speed of 79.6 m/s at ground level.

Dimas [21]

Answer:

The rocket is motion above the ground for 44.7 s.

Explanation:

The equations for the height of the rocket are as follows:

y = y0 + v0 · t + 1/2 · a · t²

and, after the engine fails:

y = y0 + v0 · t + 1/2 · g · t²

Where:

y = height of the rocket at time t

y0 = initial height

v0 = initial speed

t= time

a = acceleration due to the engines

g = acceleration due to gravity

First, let´s calculate the time the rocket is being accelerated by the engines:

(The center of the framer of reference is located at the ground, y0 = 0).

y = y0 + v0 · t + 1/2 · a · t²

1190 m = 0 m + 79.6 m/s · t + 1/2 · 4.10 m/s² · t²

0 = 2.05 m/s² · t² + 79.6 m/s · t - 1190 m

Solving the quadratic equation:

t = 11.5 s (the other value of t is discarded because it is negative).

At that time, the engines fail and the rocket starts to fall. The equation of the height will be:

y = y0 + v0 · t + 1/2 · g · t²

The initial velocity (v0) will be the velocity acquired during 11.5 s of acceleration plus the initial velocity of launch:

v = v0 + a · t

v = 79.6 m/s + 4.10 m/s² · 11.5 s

v = 126.8 m/s

Now, we can calculate the time it takes the rocket to reach the ground (y = 0) from a height of 1190 m:

y = y0 + v0 · t + 1/2 · g · t²

0 m = 1190 m + 126.8 m/s · t - 1/2 · 9.80 m/s² · t²

Solving the quadratic equation:

t = 33.2 s

Then, the total time the rocket is in motion is (33.2 s + 11.5 s) 44.7 s

5 0

3 years ago

find the average velocity of a bicycle that starts 100km south and is 120km south of town after 0.4 hours

dusya [7]

Answer:

The average velocity is 50 km/h south

Explanation:

The average velocity of an object is its total displacement divided by

the total time taken.

That means it is the rate at which an object changes its position from

one place to another.

Average velocity is a vector quantity.

The SI unit is meters per second.

A bicycle that starts 100 km south and is 120 km south of town after

0.4 hour.

The displacement = 120 - 100 = 20 km south

The time = 0.4 hour

The average velocity = $\frac{D}{T}$ , where D is the displacement

and t is the time

The average velocity of the bicycle = $\frac{20}{0.4}=50$ km/h

The average velocity is 50 km/h south

If you want it in meter per second, change the kilometer to meter

and change the hour to seconds

1 km = 1000 m

1 hour = 60 × 60 = 3600 seconds

The average velocity of the bicycle = $\frac{50(1000)}{3600}=13.89$ m/s south

5 0

2 years ago