A car is moving at 20 m/s when the driver sees a stop sign and comes to rest at 65m. How long does the car take to come to rest?

If an X-ray beam of wavelength 1.4 × 10-10 m makes an angle of 20° with a set of planes in a crystal causing first order constru

Flura [38]

Answer:

43.16°

Explanation:

λ = Wavelength = 1.4×10⁻¹⁰ m

θ₁ = 20°

n can be any integer

d = distance between the two slits

Since for the first bright fringe, n₁ = 1

n₂ = 2 for second order line

The relation between the distance of the slits and the angle through which it is passed is:

dsinθ=nλ

As d and λ are constant

$\frac{n_1\lambda}{sin \theta_1}=\frac{n_2\lambda}{sin \theta_2}\\\Rightarrow \frac{1}{sin20}=\frac{2}{sin\theta_2}\\\Rightarrow sin\theta_2=\frac{2}{\frac{1}{sin20}}\\\Rightarrow \theta_2=sin^{-1}{\frac{2}{\frac{1}{sin20}}}\\\Rightarrow \theta_2=43.16^{\circ}$

∴ Angle by which the second order line appear is 43.16°

5 0

2 years ago

the Earth exerts a gravitational force of 500 newtons on an object what is the mass of the object in kilograms

MAXImum [283]

Use Newton's second law F = mass * acceleration
In your problem F = 500, and we know gravity is working on it so use a = 9.81
Substitute into the equation
500 = m * 9.81
m = 50.97 kg

7 0

2 years ago

Differentiate between adhesion and cohesion.

sergiy2304 [10]

<h2>Answer:</h2>

<h2>Cohesion </h2>

Is the attraction that molecules have for others of their same type.

<h2>Adhesion </h2>

Is the attraction that molecules have for others of different type by intermolecular forces.

A good example of both is water that can stick to itself through hydrogen bonds (cohesion) and can also stick to a glass due to adhesion.

So, while Cohesion is the force of attraction between adjacent particles within the same body, Adhesion is the interaction between the surfaces of different bodies.

8 0

2 years ago

Matthew throws a ball straight up into the air. It rises for a period of time and then begins to drop. At which points in the ba

PolarNik [594]

Answer:

If air resistance is taken as negligible, then the ball is in freefall the moment it is thrown so gravity is the only force acting on the object. If air resistance is not negligible then gravity will be the greatest force acting on the ball while it is going up and coming down, because Fair has to be less than gravity at all times otherwise the atmosphere would wither away.

3 0

3 years ago

Scientific work is currently underway to determine whether weak oscillating magnetic fields can affect human health. For example

ValentinkaMS [17]

Answer:

$2.02672\times 10^{-11}\ V$

Explanation:

f = Frequency = 75 Hz

B = Magnetic field = $1\times 10^{-3}\ T$

d = Diameter of cell = $7.4\ \mu m$

t = Time taken

$\omega$ = Angular frequency

The expression of emf is

$E=NAB\omega sin\omega t$

Emf is maximum when $sin\omega t=1$ and N = number of turns = 1

$E_m=AB\omega\\\Rightarrow E_m=\pi \left(\frac{d}{2}\right)^2 \times B \times 2\pi\times f\\\Rightarrow E_m=\pi \left(\frac{7.4\times 10^{-6}}{2}\right)^2\times 1\times 10^{-3}\times 2\pi\times 75\\\Rightarrow E_m=2.02672\times 10^{-11}\ V$

The maximum emf that can be generated around the perimeter of a cell in this field is $2.02672\times 10^{-11}\ V$

4 0

2 years ago