pleeease help meeeeee
during a journey, a car travels at 40 km in 2.5 hours, next 62 km in 3 hours, then took a break for 30 minutes, again travelled the last 120 km in 3.2 hours. calculate the average speed of the car during the journey.

Answer:

Explanation:

We need to find the x-components of each of these vectors and then add them together, then we need to find the y-components of these vectors and then add them together. Let's get to that point first. That's hard enough for step 1, dontcha think?

The x-components are found by multiplying the magnitude of the vectors by the cosine of their respective angles, while the y components are found by multiplying the magnitude of the vectors by the sine of their respective angles.

Let's do the x-components for all the vectors first, so we get the x-component of the resultant vector:

[tex]F_{1x}=12 cos0[/tex] and

[tex]F_{1x}=12[/tex]

[tex]F_{2x}=9cos90[/tex] and

[tex]F_{2x}=0[/tex]

[tex]F_{3x}=15 cos126.87[/tex] and

[tex]F_{3x}=-9.0[/tex]  (the angle of 126.87 is found by subtracting the 53.13 from 180, since angles are to be measured from the positive axis in a counterclockwise fashion).

That means that the x-component of the resultant vector, R, is 3.0

Now for the y-components:

[tex]F_{1y}=12sin0[/tex] and

[tex]F_{1y}=0[/tex]

[tex]F_{2y}=9sin90[/tex] and

[tex]F_{2y}=9[/tex]

[tex]F_{3y}=15sin126.87[/tex] and

[tex]F_{3y}=12[/tex]

That means that the y-component of the resultant vector, R, is 21.

Put them together in this way to find the resultant magnitude:

[tex]R_{mag}=\sqrt{(3.0)^2+(21)^2}[/tex] which gives us

[tex]R_{mag}=21[/tex] and now for the angle. Since both the x and y components of the resultant vector are positive, our angle will be where the x and y values are both positive in the x/y coordinate plane, which is Q1.

The angle, then:

[tex]tan^{-1}(\frac{21}{3.0})=82[/tex] degrees, and since we are QI, we do not add anything to this angle to maintain its accuracy.

To sum up: The resultant vector has a magnitude of 21 N at 82°

Answer:

average speed is 60km/h

Explanation:

you sum up the speed attained in each distance covered and divide it by 2 to get your answer

KE = (0.5) m v²

given that : v = speed of the bottle in each case = 4 m/s when m = 0.125 kg

KE = (0.5) m v² = (0.5) (0.125) (4)² = 1 J

when m = 0.250 kg KE = (0.5) m v² = (0.5) (0.250) (4)² = 2 J

when m = 0.375 kg KE = (0.5) m v² = (0.5) (0.375) (4)² = 3 J

when m = 0.0.500 kg KE = (0.5) m v² = (0.5) (0.500) (4)² = 4 J

Answer:

a) Pascal is a derived unit because it is derived from the unit of force and area

b)Mass is a fundamental quantity because it doesn't depends upon others physical quantity and made up of only one unit

c) unit of power is a derived unit because they are dependent quantities

D) unit of length is a fundamental unit because it cannot be expressed in terms of another quantity.

Answer:

The position is 8.18cm from the mirror.

Nature is b=virtual

Size is 1.82cm

Explanation:

Note that for a convex mirror, the image distance and the focal length are negative;

Given

Object height H0 = 4cm

object distance u = 18cm

Radius of curvature R = 30cm

Since f = R/2

f = 30/2

f = -15cm

Recall that:

[tex]\frac{1}{f} =\frac{1}{u}+ \frac{1}{v}\\\frac{1}{-15}=\frac{1}{18}+\frac{1}{v} \\\frac{1}{v} =\frac{1}{-15} -\frac{1}{18}\\ \frac{1}{v} = \frac{-18-15}{270}\\\frac{1}{v} = \frac{-33}{270}\\v=\frac{-270}{33}\\v=-8.18cm[/tex]

Since the image distance is negative, this shows that the image is a virtual image.

To get the size:

[tex]\frac{H_1}{H_0}=\frac{v}{u}\\\frac{H_1}{4}=\frac{8.18}{18}\\18H_i=32.72\\H_i=\frac{32.72}{18}\\H_i= 1.82cm[/tex]

Answer:

c

Explanation:

Answer:

cant see picture

Explanation:

Answer:

please add picture so i can help you

Explanation:

Answer:

Frequency of the tuning fork[second resonance] = 512 Hz (Approx.)

Explanation:

Given:

Speed of sound = 340 m/s

Length of resonance position above a closed air column = 49.8 cm = 0.498 m

Find:

Frequency of the tuning fork

Computation:

Frequency of the tuning fork[second resonance] = 3v / 4l

Frequency of the tuning fork[second resonance] = 3(340) / 4(0.498)

Frequency of the tuning fork[second resonance] = 512.04

Frequency of the tuning fork[second resonance] = 512 Hz (Approx.)

Answer:

The frequency is 512 Hz.

Explanation:

speed, v = 340 m/s

length, L = 49.8 cm = 0.498 m

let the frequency is f.

[tex]f =\frac{3 v}{4 L}\\\\f = \frac{3 \times 340 }{4\times 0.498}\\\\f = 512 Hz[/tex]

Answer:

 ΔR = 5 s

Explanation:

The absolute uncertainty or error in an expression is

       ΔR = | [tex]\frac{dR}{dB}[/tex] | ΔB + | [tex]\frac{dR}{dA}[/tex] | ΔA

the absolute value guarantees to take the unfavorable case, that is, the maximum error.

We look for the derivatives

       [tex]\frac{dR}{dB}[/tex] = 1

       [tex]\frac{dR}{dA}[/tex] = -1

we substitute

       ΔR = 1 ΔB + 1 ΔA

of the data

       ΔB = 3 s

       ΔA = 2 s

       ΔR = 3 + 2

       ΔR = 5 s

Answer:

Increasing

Explanation:

I Hope it Helps

Answer:

The time required is 0.45 s.

Explanation:

Height, h = 1 m

initial velocity, u = m/s

Let the time is t.

Use second equation of motion

[tex]h = u t + 0.5 at^2\\\\1 = 0 +0.5 \times 9.8 \times t^2\\\\t = 0.45 s[/tex]

Explanation:

125 is your answer........

Explanation:

→ Volume of cone = πr² × h/3

Here,

→ Volume of cone = π(13)² × 27/3 cm³

→ Volume of cone = 169π × 9 cm³

→ Volume of cone = 1521π cm³

→ Volume of cone = 1521 × 22/7 cm³

→ Volume of cone = 33462/7 cm³

→ Volume of cone = 4780.28 cm³

Answer:

4,778.4 is correct

Explanation:

Answer:

2min

Explanation:

i think it will be clear from photo

Answer: The formula for current is charge/time

so here we have to change subject so we are asked to look for time  

Explanation: so it would be T=Q/I

T=4/2

T=2s

hope this helpss

Answer:

Use the formula ∆H = m x s x ∆T to solve.

Explanation:

Once you have m, the mass of your reactants, s, the specific heat of your product, and ∆T, the temperature change from your reaction, you are prepared to find the enthalpy of reaction. Simply plug your values into the formula ∆H = m x s x ∆T and multiply to solve.

Answer:

1.67 amperes

Explanation:

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

[tex] V = IR [/tex]  ......equation 1

Where;

Making I the subject of formula, we have;

[tex] I = \frac {V}{R} [/tex]  .....equation 2

Given the following data;

To find the current flowing through the battery, we would use eqn 2;

[tex] I = \frac {10}{6} [/tex]  

Current, I = 1.67 amperes

Answer:

An artificial satellites revolves around the earth under the influence of its gravitational force. So it does not require any energy to revolve around energy.

or maybe god:)))(

Answer:

They transform energy

Explanation:

thermodynamics deals with transfers of energy from one place to another and from one form to another and it's also deal with the relationship between heat and other forms of energy

Answer:

1 KM per minute is the real speed in minutes, turn that into 1000 meters per minute and divided by 60, you get a good number of 16.6666666667 which means you could go 50 meters per 3 seconds

Explanation:

so it would be 16.6666666667 meters per second

Answer:

B

Explanation:

According to boyle's law for a gas the pressure and volume are inversely proportional.this simply means when one increases the other one reduces and when the other one reduces the other increases.so in this case the volume increased to twice it original amount meaning the pressure will reduce to half the volume.

I hope this helps

Answer:

A) 111 N

B) F_net = 0 N

C) 100 N, in the opposite direction of the motion.

D) μ = 0.3274

Explanation:

A) The component of the trunks weight acts parallel to the plane but in the vertical direction and so;

W = Fsin θ

W = 325 sin 20

W = 325 × 0.3420

W ≈ 111 N

B) We are told the trunk is moving with a constant velocity and for this reason the sun of the forces will equal to zero.

Thus; F_net = 0 N

C) Since the kinetic friction force needs to balance the component of the weight, the magnitude is;

F_f = 211 - 111 = 100 N

The direction will be in the opposite direction since it's against the motion.

D) From friction formula, we know that;

F_f = μW cos θ

100 = μ × 325 × cos 20

μ = 100/(325 × cos 20)

μ = 0.3274

Answer:

m=0.2kg=200g

Explanation:

F=2N, a=10m/s²

F=ma⇒ m=F/a=2/10=0.2kg=200g

Answer:

[tex]\boxed {\boxed {\sf 200 \ grams}}[/tex]

Explanation:

According to Newton's Second Law of Motion, force is the product of mass and acceleration.

[tex]F=m*a[/tex]

The force is 2 Newtons and the acceleration is 10 meters per square second. First, we should convert the units of Newtons to make unit cancellation easier. 1 Newton is equal to 1 kilogram meter per second squared. The force of 2 N equals 2 kg*m/s²

Substitute the known values into the formula.

[tex]2 \ kg*m/s^2 = m * 10 \ m/s^2[/tex]

We are solving for the mass, so we must isolate the variable m. It is being multiplied by 10 meters were second squared. The inverse of multiplication is division. Divide both sides by 10 m/s².

[tex]\frac { 2 \ kg *m/s^2}{10 \ m/s^2}=\frac{ m* 10 m/s^2}{10 \ m/s^2}[/tex]

[tex]\frac { 2 \ kg *m/s^2}{10 \ m/s^2}= m[/tex]

The units of meters per second squared cancel.

[tex]\frac { 2 \ kg}{10}= m[/tex]

[tex]0.2 \ kg =m[/tex]

Now, we must convert the mass to grams. There are 1000 grams in 1 kilogram. We can multiply the mass by 1000 or set up a ratio.

[tex]0.2 \ kg * \frac{1000 \ g}{1 \ kg}= 0.2 * 1000 \ g = 200 \ g[/tex]

The toy car's mass is 200 grams.

Answer:

New force = 0.063 N

Explanation:

Given that,

The electric force between two charges is[tex]4.2\times 10^{-2}\ N[/tex]

The formula for the electric force is:

[tex]F=\dfrac{kq_1q_2}{r^2}[/tex]

If the distance between the charges is doubled, r' = 2r and one of the charges is tripled, q₁' = 2q₁, q₂' = 3q₂

Put all the values,

[tex]F'=\dfrac{kq_1'q_2'}{r'^2}\\\\\dfrac{F}{F'}=\dfrac{\dfrac{kq_1q_2}{r^2}}{\dfrac{kq_1'q_2'}{r'^2}}\\\\\dfrac{F}{F'}=\dfrac{\dfrac{q_1\times q_2}{r^2}}{\dfrac{2q_1\times 3q_2}{(2r)^2}}\\\\\dfrac{F}{F'}=\dfrac{4}{6}=\dfrac{2}{3}\\\\F'=\dfrac{3\times 4.2\times 10^{-2}}{2}\\\\F'=0.063\ N[/tex]

So, the new force is 0.063 N.

Answer:

The force becomes 0.0315 N.

Explanation:

Force, F = 4.2 x 10^-2 N

When the distance is doubled, a charge is tripled, Let the force is F'.

The force between the two charges is

[tex]F = \frac{K qq'}{r^2}\\[/tex]

when, q' = 3 q' and r is 2 r so

[tex]F' = \frac{K 3qq'}{4r^2} = \frac{3 F}{4} = \frac {3\times 4.2\times 10^{-2}}{4}=0.0315 N[/tex]

Answer:

1. 7.5 m

2. towards west side

explanation:

I hope it will help you