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2 years ago

Physics A-Level, both of these questions

Physics

1 answer:

podryga [215]2 years ago

8 0

I can only help you with question 7
B is the right answer.
A is wrong because when the angle is critical angle the light leaves medium 1 parallel to the surface.
C is wrong because light reflects only when travelling from a denser to a rarer/less dense medium.speed of light is lower in denser medium.
D is wrong because the frequency of the light doesn't change when travelling from one medium to another.

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On his honeymoon, James Joule attempted to explore the relationships between various forms of energy by measuring the rise of te

Marizza181 [45]

Answer:

The maximum temperature rise = 0.047 °C

Explanation:

Potential Energy, P = mgh

Energy transfered, Q=mcΔT

Potential energy = Energy transfered

mgh = mcΔT

gh = cΔT

ΔT = gh/c

ΔT = (9.81 * 20) / 4186

ΔT = 0.047 °C

8 0

3 years ago

How do I solve such problem???

labwork [276]

1). Calculate how long it takes an object to fall 4,000 m after it's dropped. (Use D = (1/2) (g) (T²) . D is 4,000 m. g = 9.8 m/s². Find T .)

2). Calculate how far the object will move HORIZONTALLY in that length of time, if it's moving at 75 m/s. (Distance = (75 m/s) x (time) . )

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3 years ago

An Olympic track runner starts from rest and has an acceleration of 2.4 m/s2 for 3.6 s, then has zero acceleration for the remai

rjkz [21]

Answer:

The runner's speed at the following times would remain 8.64 m/s.

Explanation:

Acceleration definition: Acceleration is rate of change in velocity of an object with respect to time.

In this case, after 3.6 seconds the acceleration is zero, it means that the velocity of the runner after 3.6 seconds is not changing and it will remain constant for the remainder of the race. Now, we have to find the velocity of the runner that he had after 3.6 seconds and that would be the runner's speed for the remainder of the race. For this we use first equation of motion.

First equation of motion: Vf = Vi + a×t

Vf stands for final velocity

Vi stands for initial velocity

a stands for acceleration

t stands for time

In the question, it is mentioned that the runner starts from rest so its initial velocity (Vi) will be 0 m/s.

The acceleration (a) is given as 2.4 m/s²

The time (t) is given as 3.6 s

Now put the values of Vi, a and t in first equation of motion

Vf = Vi + a×t

Vf = 0 + 2.4×3.6

Vf = 2.4×3.6

Vf = 8.64 m/s

So,the runner's speed at the following times would remain 8.64 m/s.

5 0

2 years ago

The graph below shows the velocity of a car over time.

jekas [21]

Answer:

D. Calculate the area under the graph.

Explanation:

The distance made during a particular period of time is calculated as (distance in m) = (velocity in m/s) * (time in s)

You can think of such a calculation as determining the area of a rectangle whose sides are velocity and time period. If you make the time period very very small, the rectangle will become a narrow "bar" - a bar with height determined by the average velocity during that corresponding short period of time. The area is, again, the distance made during that time. Now, you can cover the entire area under the curve using such narrow bars. Their areas adds up, approximately, to the total distance made over the entire span of motion. From this you can already see why the answer D is the correct one.

Going even further, one can make the rectangular bars arbitrarily narrow and cover the area under the curve with more and more of these. In fact, in the limit, this is something called a Riemann sum and leads to the definition of the Riemann integral. Using calculus, the area under a curve (hence the distance in this case) can be calculated precisely, under certain existence criteria.

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3 years ago

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What step of the rock cycle happens as the sea stacks are broken down

fiasKO [112]

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2 years ago

Read 2 more answers