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IRISSAK [1]
3 years ago
5

If a vector 2ỉ +3j +8k is perpendicular to the vector 4j-4i + ak, then the value of a is

Physics
1 answer:
natita [175]3 years ago
4 0

Explanation:

if two vectors are perpendicular to each other then thier dot product is equal to zero so (2i+3j+8k).(-4i+4j+ak)=0 (2)(-4) +(3)(4)+(8)(a) =0 -8+12+8a=0 4+8a=0 8a=-4

a =  \frac{ - 4}{8}

a =  \frac{ - 1}{2}

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A Formula One race car with mass 770.0 kg is speeding through a course in Monaco and enters a circular turn at 235.0 km/h in the
Marat540 [252]

Answer:

Explanation:

Given

mass of first car m_1=770 kg

speed =235 km/h\approx 65.27 m/s

radius of first turn=125 m

And Angular momentum is given by =mvr

Angular momentum of first car

L_1=770\times 65.27\times 125=6282,237.5 N-m/s

v_2=190\approx 52.77 m/s

r_2=100m

similarly L_2=770\times 52.77\times 100=4063290 N-m/s

\frac{L_1}{L_2}=\frac{r_1v_1}{r_2v_2}=\frac{125\times 65.27}{100\times 52.77}=1.546

Thus angular momentum of first car is 1.54 times of second one

4 0
4 years ago
Queremos diseñar un montacargas que pueda subir con una rapidez de 12 km/h una mas 700 kg hasta 40 m de altura en un minuto. Cal
Mariulka [41]

Answer:

a) El trabajo realizado es de 274,680 J

b) La potencia de la carretilla elevadora es de 4578 Watts.

c) La energía cinética del montacargas es de 3.888.\overline 8 J

d) La energía potencial del montacargas es de 274.680 Joules.

e) La energía mecánica de la carretilla elevadora 278,568.\overline 8 J

Explanation:

a) Los parámetros dados son;

La velocidad de la carretilla elevadora, v = 12 km / h = 10/3 m / s

La masa que debe levantar la carretilla elevadora, m = 700 kg

La altura a la que se levantará la masa, h = 40 m

El trabajo realizado, W = Fuerza, F × Distancia, h

 La fuerza, F aplicada = El peso de la carga = Masa, m × Gravedad, g

Donde 'g' es la aceleración debida a la gravedad ≈ 9,81 m / s²

∴ Trabajo realizado, W = 700 kg × 9,81 m / s² × 40 m = 274,680 J

b) El tiempo que se tarda en subir 40 m = 1 minuto = 60 segundos

∴ Potencia = Trabajo / tiempo

Por lo tanto, la potencia del montacargas, P = 274,680 J / (60 s) = 4578 Watts

c) Energía cinética, K.E. = 1/2 · m · v²

La energía cinética de la carretilla elevadora, K.E. se da como sigue;

Carretilla elevadora K.E. = 1/2 × 700 kg × (10/3 m / s) ² = 3.888.\overline 8 J

d) La energía potencial del montacargas a 40 m, P.E. = m · g · h

∴ P.E. = 700 kg × 9,81 m / s² × 40 m = 274,680 Julios

e) La energía mecánica, M.E. = P.E. + K.E.

∴ M.E. = 3.888.\overline 8 J + 274,680 J = 278,568.\overline 8 J

La energía mecánica de la carretilla elevadora, M.E.= 278,568.\overline 8 J.

8 0
3 years ago
Air at 38oC and 97% relative humidity is to be cooled to 14oC and fed into a plant area at a rate of 510 m3/min. Calculate the r
bekas [8.4K]

Answer:

mass flow rate at  water condenses is 36.72 kg/min

Explanation:

given data

temperature t1 = 38°C

temperature t2 = 14°C

humidity ∅= 97 % = 0.97

rate v = 510 m³/min

to find out

mass flow rate at  water condenses

solution

by gas equation we find here mass flow rate  that is

pv = mRT

put here value and p is 0.066626 bar at 38°C and find m

m = 0.06626 × 10^{5} × 510  / 287×311

m = 37.85 kg/min

so at water condenses mass flow rate is express as

∅ = M / m

Mass flow rate M = ∅ × m

M = 0.97 × 37.85

mass flow rate = 36.72 kg/min

so mass flow rate at  water condenses is 36.72 kg/min

8 0
3 years ago
A certain string can withstand a maximum tension of 39. N without breaking. A child ties a 0.43 kg stone to one end and, holding
frez [133]

Answer:

Bottom of the circle.

Explanation:

At the top of the circle the tension and the weight contribute on being the centripetal force, at the middle of the circle only the tension contributes on being the centripetal force (the weight being perpendicular to it), while <u>at the bottom</u> of the circle the tension contributes on being the centripetal force (as always) <em>but the weight against to it</em>, so here is where the tension must be greater to allow the same centripetal force as the other cases, thus here is where the string will break.

6 0
3 years ago
Which statement correctly identifies a difference between the function of most arteries and veins?
olasank [31]

Answer:a

Explanation:

8 0
3 years ago
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