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3 years ago

10

The magnitude of the resultant of two vectors of magnitude 3 units and 4 units is 5 units. What is the angle between two vectors

?

1 answer:

Ksivusya [100]3 years ago

4 0

Explanation:

Using Cosine rule, we have 5² = 3² + 4² - 2(3)(4)(cosx).

=> cosx = 0, x = 90°.

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m_Cu * sh_CuA system consists of a copper tank whose mass is 13 kilogram , 4 kilogram of liquid water, and an electrical resisto

notsponge [240]

Answer:

T₂ = 49.3°C

Explanation:

Applying law of conservation of energy to the system we get the following equation:

Energy Supplied by Resistor = Energy Absorbed by Tank + Energy Absorbed by Water

E = mC(T₂ - T₁) + m'C'(T'₂ - T'₁)

where,

E = Energy Supplied by Resistor = 100 KJ = 100000 J

m = mass of copper tank = 13 kg

C = Specific Heat of Copper = 385 J/kg.°C

T₂ = Final Temperature of Copper Tank

T₁ = Initial Temperature of Copper Tank = 27°C

T'₂ = Final Temperature of Water

T'₁ = Initial Temperature of Water = 50°C

m' = Mass of Water = 4 kg

C' = Specific Heat of Water = 4179.6 K/kg.°C

Since, the system will come to equilibrium finally. Therefor: T'₂ = T₂

Therefore,

(100000 J) = (13 kg)(385 J/kg.°C)(T₂ - 27°C) + (4 kg)(4179.6 J/kg.°C)(T₂ - 50°C)

100000 J = (5005 J/°C)T₂ - 135135 J + (16718.4 J/°C)T₂ - 835920 J

100000 J + 135135 J + 835920 J = (21723.4 J/°C)T₂

(1071055 J)/(21723.4 J/°C) = T₂

<u>T₂ = 49.3°C</u>

8 0

3 years ago

If the electrons are attracted more by the nucleus because of an additional proton, what would happen to it?

Rus_ich [418]

Answer:

orbital speed of the electrons in their orbit will increase

Explanation:

As we know that centripetal force for electrons will be due to electrostatic attraction force of electron.

So it is given as

$F_e = F_c$

so we have

$\frac{(Ze)(e)}{4\pi \epsilon_0 r^2} = \frac{mv^2}{r}$

now on the left side if the force of attraction will increase and hence there must be the change in that part of equation

So here at the same position the speed of the electron

So we can say that correct answer will be

orbital speed of the electrons in their orbit will increase

4 0

3 years ago

A police officer is parked by the side of the road, when a speeding car travelling at 50 mi/hrpasses. The police car immediately

Blababa [14]

Answer:

a) time taken to catch up with speeding car is 12.25 secs

b) the police car will travel 273.8 m to catch up with the speeding car

Explanation:

Given that;

speed of car $V_{c}$ = 50 mi/hr = 22.352 m/s

acceleration of police car = 10 mi/hr = 4.47 m/s²

$V_{f}$ = 70 mi/hr = 31.29 m/s

Now time taken to reach maximum speed is t₁

so

$V_{f}$ = $V_{i}$ + at₁

we substitute

31.29 = 0 + 4.47t₁

t₁ = 31.29 / 4.47

t₁ = 7 sec

now

d₁ = 0 + 1/2 × at₁²

d₁ = 0 + 1/2 × 0 + 4.47×(7)²

d₁ = 109.5 m

so distance travelled by the speeding car in time t₁ will be

$d_{c}$ = $V_{c}$ × t₁

we substitute

$d_{c}$ = 22.352 × 7

$d_{c}$ = 156.46 m

now distance between polive car and speeding car

Δd = $d_{c}$ - d₁

Δd = 156.46 - 109.5

Δd = 46.96 m

time taken to cover Δd will be

t₂ = Δd / ( $V_{f}$ - $V_{c}$ )

t₂ = 46.96 / ( 31.29 - 22.352 )

t₂ = 46.96 / 8.938

t₂ = 5.25 sec

distance travelled by the police in time t₂ will be

d₂ = $V_{f}$ × t₂

d₂ = 31.29 × 5.25

d₂ = 164.3 m

a) How long will it take before the officer catches up to the speeding car;

time taken to catch up with speeding car;

t = t₁ + t₂

t = 7 + 5.25

t = 12.25 secs

Therefore, time taken to catch up with speeding car is 12.25 secs

b) how far will it have travelled in order to do so;

distance = d₁ + d₂

distance = 109.5 + 164.3

distance = 273.8 m

Therefore, the police car will travel 273.8 m to catch up with the speeding car

6 0

3 years ago

Two microphones are connected to a

ale4655 [162]

Answer:

344.8 m/s

Explanation:

Looking for speed of sound = meters / sec

2 meters / .0058 seconds = 344.8 m/s

5 0

2 years ago

Consider the chemical equation CH4 + 2 O2 → CO2 + 2 H2O. In this equation, CH4 is a

Dennis_Churaev [7]

$CH4+2O2=\ \textgreater \ CO2+2H2O$
Since t<span>erms which are placed left to the arrow mark are reactants and those placed right are products you can easily solve the task represented above. According to the information I've provided CH4 is reactant and it is </span><span>Fule. So, the correct answer is B.</span>

3 0

4 years ago

Read 2 more answers