When you look at yourself in the mirror, what is the approximate angle of incidence of the light rays?

What is the velocity of a narwhal that swims 76 kilometers North in 3 hours

tino4ka555 [31]

Answer:

Explanation:

Velocity is the change in displacement of a body with respect to time.

Velocity - Displacement/time

Given

displacement = 76km

Time = 3hours

Substitute the given parameters into the formula;

Velocity = 75km/3hrs

Velocity = 25km/hr

Hence the velocity of the narwhal is 25km/hr

4 0

3 years ago

A brick is thrown from a wall that is 19.2 m above the ground and hits the ground 5.00 s later. What was the initial velocity of

Brums [2.3K]

Answer:

0

Explanation:

Given the following :

Height of wall = 19.2 m

Time taken to hit the ground = 5 seconds

Acceleration due to gravity (g) = 9.8m/s ( downward motion)

The initial velocity of the object refers to the Velocity of the object at time t = 0

Initial Velocity = g × time

Initial Velocity = 9.8 × 0 = 0

5 0

2 years ago

in order to qualify for the finals in a racing event, a race car must achieve an average speed of 278 km/h on a track with a tot

Pachacha [2.7K]

The minimum average speed it must have in the second half of the event in order to qualify is 414.7 km/h.

<h3>What is average speed?</h3>

The average speed of an object is the ratio of total distance traveled by the object to the total time of motion of the object.

<h3>Total time taken by the car during the entire race</h3>

time = distance/average speed

time = (1.41 km) / (278 km/h)

time = 0.0051 hr

The car travels the first half of the race, d (¹/₂ x 1410 m) at 210 km/h;

d = 705 m = 0.705 km

t1 = 0.705/210

t1 = 0.0034 hr

<h3>time for the second half</h3>

t2 = 0.0051 - 0.0034 hr

t2 = 0.0017 hr

<h3>minimum average speed of the second half</h3>

v = d/t

v = 0.705 km / 0.0017 hr

v = 414.7 km/hr

Thus, the minimum average speed it must have in the second half of the event in order to qualify is 414.7 km/h.

Learn more about average speed here: brainly.com/question/4931057

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6 0

11 months ago

A silver sphere with radius 1.3611 cm at 23.0°C must slip through a brass ring that has an internal radius of 1.3590 cm at the s

Readme [11.4K]

Answer:

The temperature must the ring be heated so that the sphere can just slip through is 106.165 °C.

Explanation:

For brass:

Radius = 1.3590 cm

Initial temperature = 23.0 °C

The sphere of radius 1.3611 cm must have to slip through the brass. Thus, on heating the brass must have to attain radius of 1.3611 cm

So,

Δ r = 1.3611 cm - 1.3590 cm = 0.0021 cm

<u>The linear thermal expansion coefficient of a metal is the ratio of the change in the length per 1 degree temperature to its length.</u>

<u>Thermal expansion for brass = 19×10⁻⁶ °C⁻¹</u>

Thus,

$\alpha=\frac {\Delta r}{r\times \Delta T}$

Also,

$\Delta T=T_{final}-T_{Initial}$

So,

$19\times 10^{-6}=\frac {0.0021}{1.3290\times (T_{final}-23.0)}$

Solving for final temperature as:

$(T_{final}-23.0)=\frac {0.0021}{1.3290\times 9\times 10^{-6}}$

<u>Final temperature = 106.165 °C</u>

5 0

3 years ago

Rock layer that must be rich in organic matter that was subjected to heat and pressure over time during the formation of oil and

Reika [66]

The lowest rock layer is a layer that must be rich in organic matter that was subjected to heat and pressure over time during the formation of oil and gas.

<h3>What is the lowest rock layer?</h3>

The lowest rock layer refers to the lowermost part of the Earth's mantle, which is a thin rock layer (approximately 250 km).

In the Earth, the layers of rocks are progressively deposited, thereby pressing them to the bottom to generate sedimentary rocks.

The lowest rock layers on the bottom must be rich in organic matter to form fossil fuels.

Learn more about rock layers here:

brainly.com/question/25846908

5 0

1 year ago