1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
stealth61 [152]
3 years ago
15

A train at a constant 60.0 km/h moves east for 40.0 min, then in a direction 50.0 degrees east of due north for 20.0 min, and th

en west for 50.0 min. What are the (a) magnitude and (b) angle for of its average velocity during this trip?
Physics
1 answer:
son4ous [18]3 years ago
6 0

Answer:

Part a)

v = 7.57 km/h

Part b)

\theta = 67.5 degreeNorth of East

Explanation:

Speed of train towards East = 60 km/h

displacement towards East is given as

d_1 = 40 km

now it turns towards 50 degree East of North

so its distance is given as

d_2 = 20 km(sin50 \hat i + cos50\hat j)

d_2 = 15.3 \hat i + 12.8 \hat j

then finally it moves towards west for 50 min

d_3 = -50 \hat i

Now the total displacement of the train is given as

d = d_1 + d_2 + d_3

d = (40 + 15.3 - 50)\hat i + 12.8 \hat j

d = 5.3\hat i + 12.8 \hat j

now total time duration of the motion is given as

T = 40 min + 20 min + 50 min

T = 1.83 h

now average velocity is given as

v_{avg} = \frac{5.3\hat i + 12.8\hat j}{1.83}

v_{avg} = 2.89\hat i + 6.99\hat j

Part a)

magnitude of the average velocity is given as

v = \sqrt{v_x^2 + v_y^2}

v = \sqrt{2.89^2 + 6.99^2}

v = 7.57 km/h

Part b)

Direction of the velocity is given as

tan\theta = \frac{v_y}{v_x}

tan\theta = \frac{6.99}{2.89}

\theta = 67.5 degreeNorth of East

You might be interested in
Which term below best matches this definition - a period in European history when many educated people stressed the importance o
german

Answer:

The Enlightenment.

Explanation:

The Enlightenment took place during the eighteen century and it typically involved a period of philosophical, cultural and intellectual movement in which ideas on nature, reason, humanity and God were emphasized on greatly over science and superstition through meetings that were held at coffeeshops, scientific academies, literary salons, masonic lodges, etc. Some of the influential philosophers of the enlightenment were Adam Smith, John Locke, Jean Jacques Rousseau, David Hume, Baruch Spinoza, Montesquieu, Hugo Grotius, Denis Diderot, Gottfried Wilhelm, Cesare Beccaria, Immanuel Kant etc. The enlightenment was also known as the age of reason or the age of enlightenment.

Hence, the enlightenment was a period in European history when many educated people stressed the importance of learning and reasoning; education was considered the key to understanding and solving society's problems.

5 0
2 years ago
A cube of wood having an edge dimension of 20.0cm and a density of 650 kg /m³ floats on water. (b) What mass of lead should be p
schepotkina [342]

The mass added is "m" so the complete cube is submerged in the water is 2.8 kg.

<h3>What mass of lead should be placed on the cube?</h3>

Given: Side of the cube (a) = 20cm

The density of the cube (ρc) = $$650 kg/m^3

a) Applying the force balance, the buoyant force must be equal to the weight of the cube

ρcgV = ρg × (Ax)

Substituting the values in the above equation, we get

(650*(0.2 m)^3)=1000*(0.2 m)^2*x

x = 0.13

where x is the height of the cube in the water

$$A = a^2 is the area of the cross-section

ρ is the density of the water

V is the volume of the cube

Now, the height above the surface of the water would be

h = a − x

Substituting the values, then we get

h = 0.2 − 0.13

h = 0.07 m

b) The mass added is "m" so the complete cube is submerged in the water, therefore

ρcgV + mg = ρg × (V)

$(650*(0.2 m)^3)+m=1000*(0.2 m)^3

m = 2.8 kg

The mass added is "m" so the complete cube is submerged in the water is 2.8 kg.

To learn more about buoyant force refer to:

brainly.com/question/11884584

#SPJ4

7 0
1 year ago
The electrostatic attractions in crystalline salts, such as sodium chloride, are formed by __________ between positive and negat
nikklg [1K]
D transferring electrons because that causes electricity
8 0
3 years ago
Read 2 more answers
What is the minimal mass of helium (density 0.18 kg/m3) needed to lift a balloon carrying two people in a basket, if the total m
Sergio039 [100]

Answer:   
 M[min] = M[basket+people+ balloon, not gas] * ΔR/R[b] 
 Î”R is the difference in density between the gas inside and surrounding the balloon. 
 R[b] is the density of gas inside the baloon.   
 ==================================== 
 Let V be the volume of helium required. 
 Upthrust on helium = Weight of the volume of air displaced = Density of air * g * Volume of helium = 1.225 * g * V   
 U = 1.225gV newtons 
 ---- 
 Weight of Helium = Volume of Helium * Density of Helium * g 
 W[h] = 0.18gV N   
 Net Upward force produced by helium, F = Upthrust - Weight = (1.225-0.18) gV = 1.045gV N  -----

 
 Weight of 260kg = 2549.7 N 
 Then to lift the whole thing, F > 2549.7 
 So minimal F would be 2549.7 
 ---- 
 1.045gV = 2549.7 
 V = 248.8 m^3   
 Mass of helium required = V * Density of Helium = 248.8 * 0.18 = 44.8kg (3sf)   
 =====   
 Let the density of the surroundings be R 
 Then U-W = (1-0.9)RgV = 0.1RgV   
 So 0.1RgV = 2549.7 N 
 V = 2549.7 / 0.1Rg   
 Assuming that R is again 1.255, V = 2071.7 m^3 
 Then mass of hot air required = 230.2 * 0.9R = 2340 kg   
 Notice from this that M = 2549.7/0.9Rg * 0.1R so   
 M[min] = Weight of basket * (difference in density between balloon's gas and surroundings / density of gas in balloon)   
 M[min] = M[basket] * ΔR/R[b]
3 0
3 years ago
1- A 30 gram bullet travels at 300 m/s. How much kinetic energy does it have?
labwork [276]

Answer:

1.35 kJ  

Explanation:

KE = ½mv² = ½ × 0.030  kg × (300 m·s⁻¹)² = 1350 J = 1.35 kJ

7 0
3 years ago
Read 2 more answers
Other questions:
  • Ajdaifsgodtistizhxtsgoachoach
    13·1 answer
  • Of the seven chambers in the masque of the red death, which room is the least popular, and why?
    8·1 answer
  • If the acceleration was reduced 1/4 what will be the new force
    7·1 answer
  • What is radiation? What are the different types? ​
    15·2 answers
  • When applying Gauss' law for a capacitor containing a dielectric, which of the following statements is false? (Latter part of se
    12·1 answer
  • A series of pulses of amplitude 0.28 m are sent down a string that is attached to a post at one end. The pulses are reflected at
    14·2 answers
  • Ultraviolet light of wavelength 3500 Angstrom falls on a potassium surface. The maximum energy of the emitted photoelectrons is
    11·1 answer
  • A 50-cm-long spring is suspended from the ceiling. A 290 g mass is connected to the end and held at rest with the spring unstret
    9·1 answer
  • Science help please!!!!!!!!!!!!!!!!!!!
    9·2 answers
  • I need help. It's 9th grade physical science
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!