Use the right-hand rule for magnetic force to determine

rodikova [14]

Answer: First option

Explanation: The higher the frequency, the higher the energy.

λν=c where λ is the wavelength, ν is the frequency and c is the speed of light. So when wavelength decreases, v increases and so does energy.

An AM radio wave has a very long wavelength. It therefore has a very low frequency and low energy.

A light wave has a very short wavelength. It therefore has a high frequency and high energy.

3 0

3 years ago

wo ships, one 200200 metres in length and the other 100100 metres in length, travel at constant but different speeds. When trave

shutvik [7]

Answer:

The speed of the faster ship is 22.5 m/s

Explanation:

The length of the ships are;

Ship 1 = 200 m

Ship 2 = 100 m

The time it takes for the ships to completely cross each other when travelling in opposite directions = 10 seconds

The time it takes both ships to cross each other when travelling in the same direction = 25 seconds

Let x represent the speed of the first ship, ship 1, and y represent the speed of the second ship, ship, 2, we have;

(x + y) × 10 = 200 + 100 = 300

10·x + 10·y = 300...(1)

(x - y) × 20 = 200 + 100 = 300

20·x - 20·y = 300...(2)

Multiply equation (1) by 2, to get;

(x + y) × 10 × 2 = 300 × 2

20·x + 20·y = 600...(3)

Adding equation (1) to equation (3) gives;

20·x + 20·y + 20·x - 20·y = 600 + 300

40·x = 900

x = 900/40 = 22.5

x = 22.5

The speed of the first ship, ship 1 = x = 22.5 m/s

From equation (1), we have;

10·x + 10·y = 300

y = (300 - 10·x)/10 = (300 - 10×22.5)/10 = 7.5

y = 7.5

The speed of the second ship, ship 2 = y = 7.5 m/s

Therefore, the faster ship is ship 1 with a speed of 22.5 m/s

7 0

3 years ago

Calculate the energy absorbed when 13 kg of liquid water raises from 18°C to 100°C and then boils at 100°C.

Cloud [144]

Answer:

the energy absorbed is 4.477 x 10⁶ J

Explanation:

mass of the liquid, m = 13 kg

initial temperature of the liquid, t₁ = 18 ⁰C

final temperature of the liquid, t₂ = 100 ⁰C

specific heat capacity of water, c = 4,200 J/kg⁰C

The energy absorbed is calculated as;

H = mcΔt

H = mc(t₂ - t₁)

H = 13 x 4,200(100 - 18)

H = 4.477 x 10⁶ J

Therefore, the energy absorbed is 4.477 x 10⁶ J

5 0

3 years ago

4-year-old becomes frightened of the dark and refuses to go to sleep at night. How would a psychoanalyst and a behaviorist diffe

inessss [21]

Answer:

A psychoanalyst would see the 4-year-old as having an unresolved conflict where the brain judges or evaluates how good or bad the darkness is, or the usefulness of sleeping in the dark at night based on a comparison, due to the child's exploration of the world around him. A psychoanalyst might see the child's refusal to sleep at night due to the dark as a fear created for instance when the child sleeps alone without the parent. This might change if the child sleeps at night beside the parent in the dark.

While behaviorists would look at how having previous negative experiences in the dark influences a child's behavior towards staying in the dark. This fear would be reinforced with more negative experiences in the dark such as having a bad nightmare whenever the child sleeps in the dark, a feeling of hearing, or seeing strange things while in the dark. These examples would have built a behavioral pattern where the child would be conditioned to respond fearfully to being in the dark.

8 0

3 years ago

Bill and Amy want to ride their bikes from their neighborhood to school which is 14.4 kilometers

Vedmedyk [2.9K]

First we should convert 14.4 km into meters using the conversion factor 1km = 1000m; thus, 14.4 km = 14,400 m. Next, we should convert all minutes into seconds <span>using the conversion factor 1 min = 60 seconds; thus, 40 mins = 2400 seconds while 20 minutes = 1200 seconds.
Speed = distance over time
Amy's speed = 14400 m / 2400 sec = 6m/s
Bill's time is 1200 sec + Amy's which is 2400 sec
Bill's speed = 14400m / 3600 sec = 4 m/s

Therefore, Amy is faster than Bill with 2 m/s difference.</span>

3 0

3 years ago