An object moving at a constant velocity accelerates at a constant rate of 2.5 m/s2 for a distance of 30 m. At the end of the acceleration the object has a velocity of 90 m/s. What was its velocity before accelerating?

Answer: A negatively-charged ion always has more electrons than protons

Explanation:

First, we know that the elementary negative charge is the electron, while the positive one is the proton. Such that both have the same charge in magnitude, but a different sign. Such that if we have the same number of electrons and protons in an atom, the charge of this atom will be neutral.

And an ion is an atom with a different number of electrons and protons, so the charge of the atom is not neutral.

Then if we have a negatively-charged ion, the charge of this atom is negative. Then we must have a larger number of electrons (the negative ones) than protons (the positive ones)

Then the correct option is:

A negatively-charged ion always has more electrons than protons

Answer:

Average Power = 14599.24 W

Explanation:

We know that :

[tex]power = \frac{work \: done}{time} [/tex]

[tex]work \: done \: = force \times displacement \: \cos( \alpha ) [/tex]

Acceleration of car (a) = v - u / t

= 13. 8 - 0 / 13.5

= 1.02 m / sec ^2

Displacement (s) = v^2 / 2a

= 13.8 * 13.8 / 2.04

= 93.35 m

Now,

Resultant force = F (Car) - F (Resistance) = m * a

Force (Car) = m * a + Force (Resistance)

Force (Car) = 1744.2 + 367.1 = 2111.3 N

Work done by Car = Force (Car) * Displacement

= 2111.3 * 93.35 * Cos 0°

= 197089.85 J

Average Power = Work Done / time

= 197089.85 J / 13.5 sec

= 14599.24 W

The average speed of the skier as shown in the image  is 2.33 m/s.

Average speed is the ratio of the total distance covered to the total time taken  ot cover the distance.

To calculate the average speed of the skier, we use the formula below.

Formula:

Where:

From the question,

Given:

Suibstitute these values into equation 1

Hence, the average speed of the skier is 2.33 m/s.

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Answer:

d = 4[m]

Explanation:

Torque in physics is defined as the product of force by distance. This way you can use the following equation to calculate the torque.

[tex]T=F*d[/tex]

where:

T = torque [N*m]

F = force [N]

d = distance [m]

Now replacing in the equation above.

[tex]84=21*d\\\\d= 4[m][/tex]

Answer:

Explanation:

V_{1} = first volume

V_{2} = second volume

T_{1} = first temperature

T_{2} = second temperature

Answer:

692.4m/s

Explanation:

According to Newton's second law;

F = ma

F = m(v-u)/t

m is the mass

v is the final velocity

u is the initial velocity

t is the time

F is the forcr

Given

F = 450N

m = 2800kg

u =690m/s

t =15s

v = ?

Substitute into the formula

450 = 2800(v-690)/15

450×15 = 2800(v-690)

6750 = 2800(v-690)

6750/2800 =v-690

2.4 = v-690

v = 690+2.4

v = 692.4m/s

Hence the final velocity is 692.4m/s

Answer:

Gravity creates stars and planets by pulling together the material from which they are made.

Explanation: Thats the only thing i have im stuck on the tga quiz

Answer: B. Mechanical Waves

Explanation:

Answer:

Good:

Quarrying creates jobs in areas where there are limited opportunities.

There is a huge demand for the products of quarrying, such as building stone and cement. ...

Quarrying provides income to local councils through taxation.

Good communications are needed for transporting the products of quarrying.

Bad: Quarrying creates pollution from noise and dust.

Heavy traffic causes pollution and congestion on narrow country roads. ...

Quarries create visual pollution and tourists may be deterred by the scars on the landscape.

Explanation:

Answer:

fdhjyegshdrhjfsdffddfnfdhdfkjdfkjkjdfijldfjkdfndfkjhdfbhjfdjdfhhjdfhj

Explanation:

Answer:

The acceleration caused by a net force of 2 N on a 2 kg mass is 1 m/s²

Explanation:

The given parameters on an applied force is as follows;

The acceleration given to a 1 kg mass by a 1-N net force = 1 m/s²

According to Newton's second law of motion, the acceleration, "a", given to an object by a force, "F", is proportional to the magnitude of the net force

Therefore, we have;

F ∝ a

The constant of proportionality is given as the mass, "m", of the object, therefore, we have;

F = m × a

The acceleration given to a 2 kg mass by a 2-N net force is given therefore, given as follows;

2 N = 2 kg × a

a = 2 N/(2 kg) = 1 m/s²

The acceleration, "a", caused by a net force of 2 N on a 2 kg mass is a = 1 m/s².

Answer:

I think the first two one is 70 the second on is 14

I hope this helps if I’m wrong I’m sorry

Explanation:

Answer:

There are two answers:

When player 1 collided with player 2, player 1's kinetic energy transferred to player 2.

Player 1 could slow down, stop , change direction, or fall, while player 2 would begin moving away from the collision point and possibly fall.

Explanation:

Answer:

25 km/h

Explanation:

speed=distance÷time

125÷5=speed

125÷5=25 (then add units)

Answer:

1.0125 x 10^19

Explanation:

current flowing through conductive wire= 9mA = 9 x 10^ -3 A

charge passing per 3 min

Q = It

= 9 x 10^ -3 x (3 x 60)

= 1.620 C

no of electrons in charge

Q = ne

1.620 = n x 1.6 x 10 ^ -19

n. = 1.0125 x 10 ^19

Answer:

A. when the Sun, Moon and Earth are in a straight line

Explanation:

The highest tide is formed when the sun, moon, and also the earth are in alignment. This high tide is known as spring tides.

Spring tides happen when we have a new moon or a full moon. With the earth, sun and moon aligning. We have lunar and solar tide forming a reinforcement with each other causing high tides or extreme tides. we have collectively, their gravitational pull on water of the earth to become stronger

Answer:

The horizontal distance traveled by the skydiver is 510.8 m.

Explanation:

Given;

height of fall, h = 800 m

initial velocity of the airplane, u = 40 m/s

The time to fall to the ground is calculated as;

[tex]t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2 \times 800}{9.81} }\\\\t = 12.77 \ s[/tex]

The horizontal distance or range of the motion is calculated as;

R = ut

R = 40 m/s x 12.77 s

R = 510.8 m

Therefore, the horizontal distance traveled by the skydiver is 510.8 m.

Given :

An inclined plane is used to lift a box into a moving truck. The ramp is 6 m long and 1.5 m.

To Find :

The mechanical advantage of the inclined plane.

Solution :

Mechanical advantage, M.A of an inclined plane is given by :

[tex]M.A = \dfrac{\text{Length of slope}}{\text{Height of plane}}[/tex]

Putting given values in above equation, we get :

[tex]M.A = \dfrac{6 \ m}{1.5 \ m}\\\\M.A = 4[/tex]

Therefore, the mechanical advantage of the inclined plane is 4.

Explanation:

Lola

Or Jasmine

Or lucy

Or Nightingale

Or Sugarcane

Or Polly

Or Heather

Some names I like!

Answer:

[tex]\mathrm{(a)\:}32,000,000\:\mathrm{Ns},\\\mathrm{(b)\:}390,000\:\mathrm{N}[/tex]

Explanation:

The impulse-momentum theorem states the impulse on an object is equal to the change in momentum of that object. Momentum is given by [tex]p=mv[/tex]. Since mass is constant, the train's change in momentum is:

[tex]\Delta p=m\Delta v=750,000\cdot42=31,500,000=\fbox{$32,000,000\:\mathrm{Ns}$}[/tex](two significant figures).

Impulse is also given as [tex]\Delta p = F\Delta t[/tex], where [tex]F[/tex] is the average force applied and [tex]\Delta t[/tex] is change in time. Since [tex]t[/tex] is given as [tex]80\mathrm{s}[/tex], we have the following equation:

[tex]F\Delta t=\Delta p\\\\F=\frac{\Delta p}{\Delta t},\\\\F=\frac{31,500,000}{80},\\\\F=393,750=\fbox{$390,000\:\mathrm{N}$}[/tex](two significant figures).

Answer:

52.802

Explanation:

"Significant figures" in Mathematics refer to the digits that give accuracy to the value of a measurement. There are specific rules when it comes to determining the significant figures. For example, all non-zero digits are considered significant and zeroes located in-between non-zero numbers are significant. In the number given above, the digit "0" is located between "8" and "1," therefore, it is significant. All the digits above are significant.

The problem is only asking for "five" significant figures. We can do this by counting from the left to the right. By this means, we know that the number will be rounded off to the nearest thousandths, which is "1." The number after 1 is 5, which means that 1 digit will be added to number 1, thus, making the digit into "2." The last digit (5) will then be removed.

Explanation:

five significant of 52.8015=52.801 ..

Answer:

The true statements are;

The median of A is the same as the median of B

The interquartile range of B is greater than the interquartile range of A

Explanation:

The given parameters are;

The set of the number of runs, A = {1, 4, 2, 2, 3, 1, 1, 2, 1}

The number of runs the pitcher allows in the tenth game = 9 runs

The set of the number of runs allowed in 10 games B = {1, 4, 2, 2, 3, 1, 1, 2, 1, 9}

Rearranging the data, we get  

A = 1, 1, 1, 1, 2, 2, 2, 3, 4

B = 1, 1, 1, 1, 2, 2, 2, 3, 4, 9

For the set A, we have;

Q₁ = 1, Q₂ = 2, Q₃ = 2

Therefore, the interquartile range of A = Q₃ - Q₁ = 2.5 - 1 = 1.5

For the set B, we have;

Q₁ = 1, Q₂ = 2, Q₃ = 2

Therefore, the interquartile range of A = Q₃ - Q₁ = 3.25 - 1 = 2.25

Therefore, the correct answers with regards to the two data are;

The median of A is the same as the median of B

The interquartile range of B is greater than the interquartile range of A

Answer:

The change in velocity is 5.5 km/h

Explanation:

The initial velocity with which the sailboat is travelling, v₁ = 10 km/h

The final velocity with which the sailboat is travelling, v₂ = 15.5 km/h

The change in velocity, Δv, is the difference between final velocity, v₂ and the initial velocity, v₁, as follows;

Mathematically, Δv = v₂ - v₁

By substituting the given values, we have;

Δv = 15.5 km/h - 10 km/h = 5.5 km/h

The change in velocity, of the sailboat Δv = 5.5 km/h.

Answer:

Initial x component of velocity: 30m/s

Initial y component of velocity: 0m/s

Explanation:

First, draw a diagram of a cliff and the object falling off the cliff as well as the initial velocity listed and the object at the bottom of the cliff with time. The object is fired horizontally, thus the initial velocity in this case 30m/s equals the horizontal initial velocity, there is no initial vertical velocity.

If the object hits the ground in 2 seconds since horizontal velocity is not affected by any other forces it will move at constant speed horizontally. However, vertically there is a gravitational force acting on the projectile converted from the potential energy of it's height. we know the gravitational constant g=-9.8m/s^2, and we can use the kinematic equation Δy=v0(t)+1/2at^2 to find the Δy(change in height of the projectile), as v0y=0, Δy=1/2at^2, a=9.8m/s^2 and t=2 seconds

thus Δy=19.6m≈20m

hope this helped

The initial X component of velocity when the projectile initially fired is 30m/s. The initial Y component of velocity when the projectile initially fired is 0m/s.

There are three equation of motions that can be used when motion of the object is under constant acceleration and on a straight path.

The vertically there is a gravitational force acting on the projectile converted from the potential energy of it's height.

The gravitational constant g =-9.8m/s^2,

we can use the equation of motion

Δy = v0(t) + 1/2at^2

The initial horizontal velocity of the projectile, Vₓ = 30 m/s

The time of the motion of the projectile, t = 2 s

The horizontal distance traveled by the projectile is given by the range of the projection as;

X = Vₓt

X = 30 x 2

X = 60 m

Thus the horizontal distance traveled by the projectile is 60 m

Hence, The initial X component of velocity when the projectile initially fired is 30m/s. The initial Y component of velocity when the projectile initially fired is 0m/s.

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Answer:

4 target heart rate. is the answer

Explanation:

hope its right

Answer:

4200 J/°C/kg

Explanation:

The formula for heat transfer is given by :

Q= m*c*ΔT  where;

Q= heat transferred = 6930 J

m=mass of the liquid = 0.330 kg

c= specific heat capacity=?

ΔT = 25-20 = 5.0°C

Applying the values in the formula as;

Q= m*c*ΔT

6930 = 0.330 * c * 5

6930 = 1.65 c

6930/1.65 = c

4200 = c

c= 4200 J/°C/kg

Answer:

elements

not really an explanation

Answer:

The amount of water vapor in the air is 90% of what the air can hold.

Explanation:

The answer is A

Answer: The answer is B: The amount of water vapor in the air is 90% of what the air can hold