Ask question

Ask question

All categories

alexandr1967 [171]

3 years ago

14

A student starts from the hostel and goes to his friend's house and then to his school. A is the displacement vector from the ho

stel to his friend's house. B is the displacement vector from his friend's house to school, and C is the direct path from the hostel to school. Which of the following vector operations is correct for the displacement from the hostel to his friend's house?
A) A - B.
B) A + B.
C) C - B.
D) C + B.

1 answer:

oksano4ka [1.4K]3 years ago

3 0

Answer: $\vec{C}-\vec{B}$

Explanation:

Given

$\vec{A}$ is displacement of student from Hostel to house

$\vec{B}$ is displacement of student from house to school

And $\vec{C}$ is displacement of student from Hostel to school

According to the triangle law of vector addition

If two vectors are acting on a body simultaneously that are shown by magnitude and direction by two sides of a triangle taken in order then the third side is the resultant of two vectors that are taken in opposite direction.

$\vec{A}+\vec{B}=\vec{C}$

$\vec{A}=\vec{C}-\vec{B}$

so option c is correct

You might be interested in

Acceleration is always measured in meters per second squared. Why is acceleration not measured in meters per second like speed?

Taya2010 [7]

Answer:

Because 'distance per second' is a velocity, not an acceleration.

Explanation:

Because 'distance per second' is a velocity, not an acceleration. For example, at 1 m/s an object is travelling a distance of 1 metre every second. But a rate of acceleration is a steady increase in velocity. So at 1 m/s^2, an object's velocity is increasing by 1 m/s every second.

6 0

2 years ago

Which of the following solid fuels has the highest heating value?

Makovka662 [10]

I wanna say its A . I could be wrong but im almost 100 percent sure that its A wood

4 0

3 years ago

In the first law of Thermodynamics ΔE = Q - W, what does ΔE stand for???

Alexxx [7]

<span>Δ</span>E = q + w

q = heat (quantity of)

q and w can be positive or negative depending on if work/heat is being absorbed/done on the system or released/done by the system

7 0

3 years ago

Read 2 more answers

Determine the speed, wavelength, and frequency of light from a helium-neon laser as it travels through polystyrene. The waveleng

klemol [59]

Answer:

Speed:

$2.01x10^{8}m/s$

Wavelength:

$4.24x10^{-7}m$

Frequency:

$4.74x10^{14}Hz$

Explanation:

The speed of the laser as it travels through polystyrene can be determine by means of the equation of the refraction index:

$n = \frac{c}{v}$ (1)

Where c is the speed of light and v is the speed of the laser in the medium.

Therefore, v will be isolated from equation 1

$v = \frac{c}{n}$

$v = \frac{3x10^{8}m/s}{1.490}$

$v = 2.01x10^{8}m/s$

Hence, the speed of the laser has a value of $2.01x10^{8}m/s$

Frenquency:

Since, wavelength is the only one who depends on the media. Therefore the frequency in both medium will be the same.

To determine the frequency it can be used the following equation

$c = \nu \cdot \lambda$ (2)

Where c is the speed of light, $\nu$ is the frequency and $\lambda$ is the wavelength

Then, $\nu$ wil be isolated from equation 2.

$\nu = \frac{c}{\lambda}$ (3)

Before using equation 3 it is necessary to express $\lamba$ in units of meters.

$\lambda = 632.8nm . \frac{1m}{1x10^{9}nm}$ ⇒ $6.328x10^{-7}m$

$\nu = \frac{3x10^{8}m/s}{6.328x10^{-7}m}$

$\nu = 4.74x10^{14}s^{-1}$

$\nu = 4.74x10^{14}Hz$

Hence, the frequency of the laser has a value of $4.74x10^{14}Hz$

Wavelength:

To determine the wavelength it can be used:

$v = \nu \cdot \lambda$

$\lambda = \frac{v}{\nu}$

Where v is the speed of the laser through the polystyrene.

$\lambda = \frac{2.01x10^{8}m/s}{4.74x10^{14}s^{-1}}$

$\lambda = 4.24x10^{-7}m$

Hence, the wavelength of the laser has a value of $4.24x10^{-7}m$

3 0

3 years ago

A thin rod of length 1.4 m and mass 140 g is suspended freely from one end. It is pulled to one side and then allowed to swing l

m_a_m_a [10]

Answer:

a The kinetic energy is $KE = 0.0543 J$

b The height of the center of mass above that position is $h = 1.372 \ m$

Explanation:

From the question we are told that

The length of the rod is $L = 1.4m$

The mass of the rod $m = 140 = \frac{140}{1000} = 0.140 \ kg$

The angular speed at the lowest point is $w = 1.09 \ rad/s$

Generally moment of inertia of the rod about an axis that passes through its one end is

$I = \frac{mL^2}{3}$

Substituting values

$I = \frac{(0.140) (1.4)^2}{3}$

$I = 0.0915 \ kg \cdot m^2$

Generally the kinetic energy rod is mathematically represented as

$KE = \frac{1}{2} Iw^2$

$KE = \frac{1}{2} (0.0915) (1.09)^2$

$KE = 0.0543 J$

From the law of conservation of energy

The kinetic energy of the rod during motion = The potential energy of the rod at the highest point

Therefore

$KE = PE = mgh$

$0.0543 = mgh$

$h = \frac{0.0543}{9.8 * 0.140}$

$h = 1.372 \ m$

5 0

3 years ago

Read 2 more answers