Explanation

a) \(\lambda = \frac{h}{p} or \alpha = \frac{h}{mV}\)

b) The significance of the equation is tha, a particle of mass (m) moving with a velocity (v) has an associated wavelength (\(\lambda\)). The wavelength decreases with increase in momentum or velocity.

Correct Answer: B. radiation

Correct Answer: B. 37.5 kΩ

Explanation

For the combination in series;

⇒R1 = 35kΩ + 40kΩ = 75kΩ

R is combined with 75kΩ in parallel to give 25kΩ

= \(\frac{1}{R_eq}\) = \(\frac{1}{R}\) + \(\frac{1}{R}\)

= \(\frac{1}{25}\) = \(\frac{1}{R}\) + \(\frac{1}{75}\)

= \(\frac{1}{25}\) - \(\frac{1}{75}\) + \(\frac{1}{R}\)

= \(\frac{3-1}{75}\) = \(\frac{1}{R}\)

= \(\frac{2}{75}\) = \(\frac{1}{R}\)

= \(\frac{75}{2}\) = R

; R = 37.5k Ω

Correct Answer: B. I only

Explanation

Transverse waves cause the medium to move perpendicular to the direction of the wave. Longitudinal waves cause the medium to move parallel to the direction of the wave. Examples of Transverse waves are water waves, light waves, radio waves and string / rope waves. Important example of Longitudnal waves is sound wave.

Correct Answer: B. change in momentum

Explanation

It is a graph that represents the force that acts on a body in a certain amount of time. Force on the object is represented by the y-axis and time taken by the object is represented by the y axis. The area under the curve indicates the impulse, the change in momentum that the object undergoes.

Correct Answer: C. diffraction of light

Correct Answer: D. 225m

Correct Answer: C) 33.3 cm

Explanation

(a)(i) Hooke's Law: This states that provided the elastic limit is not exceeded, the extension or compression of an elastic material is directly proportional to the applied force. (ii) Calculation of force constant (K): From Hooke's law:

Mg = Ke = k(l - lo)

0.3 x 10 = k(0.20- lo).. ..(i)

1.95x 10 = k(0.75 - lo) 1) ...(ii)

From (i) lo = \(\frac{3+0.20 k}{lo}\)

From (ii) 19.5 k[0.75 - 0.2 - 3/k]

: K = 30N/m

lo = 0.2 - 3/20

: lo = 0.2 - 0.1 = 0.1m

(b)(i) Definition of diffusion: This is the intimate mixing of substance due to random motion of their molecules/particles.

(b)(ii) Factors that affect the rate of diffusion: (i) Temperature of the environment. (ii) Density of the substance. (iii) Medium of diffusion. (iv) Concentration gradient.

(b)(iii) Relationship between rate of diffusion of a gas and its density:

Rate of diffusion = \(\frac{1}{√density of gas}\)

(c) Derivation of the relationship between the period T, of orbit and R:

\(\frac{MV^2}{R}\) = \(\frac{GMM}{R^2}\)

\(\frac{2πR}{T}\) = \(\frac{GM}{R}\)

\(T^2\) = \(\frac{4π^2R^3}{GM}\)

\(T^2\)α\(R^3\)

Correct Answer: A. their resistance decrease with temperature