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3 years ago

Kepler improved the Copernican model of the universe by adding : string theory

Physics

1 answer:

Mashutka [201]3 years ago

6 0

Answer:

elliptical orbits

Explanation:

the earth revolves round the sun in an elliptical form

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A motorist drives south at 24.0 m/s for 3.00 min, then turns west and travels at 25.0 m/s for 2.20 min, and finally travels nort

grigory [225]

Answer:

magnitude m = 5440.26 M

average speed is = 25.05 m/s

average velocity = 14.62 m/s

Explanation:

given data

speed v1 = 24 m/s

time t1 = 3 min = 180 s

speed v2 = 25 m/s

time t2 = 2.2 min = 132 s

speed v3 = 30 m/s

time t3 = 1 min = 60 s

total time = 6.2 min = 372 s

to find out

displacement in m and average speed and average velocity

solution

so we find here displacement

displacement = vt .............1

displacement 1 = 24 × 180 = 4220 m south = -4220 j ..........2

displacement 2 = 25 × 132 = 3300 m west = -3300 i ...........3

distance 3 = 30 × 60 = 1800 m

displacement = 1800 cos45 -i + 1800 cos45 j

displacement = -1272.79 i + 1272.79 j .............4

so total displacement D = equation 2 + equation 3 + equation 4

total displacement D = -4220 j -3300 i -1272.79 i + 1272.79 j

total displacement D = -2947.21 j - 4572.79 i

so magnitude m = √(-2947.21)² + (-4572.79)² )

so magnitude m = 5440.26 M

and

average speed is = total distance / time

average speed is = (4220 + 3300+ 1800 ) / 372

average speed is = 25.05 m/s

and

average velocity = total displacement / time

average velocity = 5440.26 / 372

average velocity = 14.62 m/s

7 0

4 years ago

43. A rocket sled accelerates at a rate of 49.0m/s2. Its passenger has a mass of 75.0 kg. (a) Calculate the horizontal component

lord [1]

(a) 3675 N

Assuming that the acceleration of the rocket is in the horizontal direction, we can use Newton's second law to solve this part:

$F_x = m a_x$

where

$F_x$ is the horizontal component of the force

m is the mass of the passenger

$a_x$ is the horizontal component of the acceleration

Here we have

m = 75.0 kg

$a_x = 49.0 m/s^2$

Substituting,

$F_x=(75.0)(49.0)=3675 N$

(b) 3748 N, 11.3 degrees above horizontal

In this part, we also have to take into account the forces acting along the vertical direction. In fact, the seat exerts a reaction force (R) which is equal in magnitude and opposite in direction to the weight of the passenger:

$R=mg=(75.0)(9.8)=735 N$

where we used

$g=9.8 m/s^2$ as acceleration of gravity.

So, this is the vertical component of the force exerted by the seat on the passenger:

$F_y = 735 N$

and therefore the magnitude of the net force is

$F=\sqrt{F_x^2+F_y^2}=\sqrt{3675^2+735^2}=3748 N$

And the direction is given by

$\theta = tan^{-1}(\frac{F_y}{F_x})=tan^{-1}(\frac{735}{3675})=11.3^{\circ}$

4 0

3 years ago

Calculate the force of an 8kg object pushing up from the table

zepelin [54]

The correct answer to the question is: 78.4 N.

CALCULATION:

As per the question, the mass of the object is given as m = 8 Kg.

We are asked to calculate the force of 8 Kg object pushing up from the table.

The force pushing up from the table is nothing else than the normal reaction.

The normal reaction of the object is equal to the weight of the object as the object is simply resting on the table.

Hence, normal reaction = Weight

= mg

= 8 × 9.8 N.

= 78.4 N.

Here, g is known as acceleration due to gravity.

Hence, the force of the object pushing up from the table is 78.4 N.

6 0

4 years ago

A chemist needs 15.0 grams of ethanol for a reaction. If the density of ethanol is 0.789 g/ml, how many milliliters of alcohol s

harina [27]

Mass=15g
Density=0.789g/ml

$\\ \bull\tt\dashrightarrow Density=\dfrac{Mass}{Volume}$

$\\ \bull\tt\dashrightarrow Volume=\dfrac{Mass}{Density}$

$\\ \bull\tt\dashrightarrow Volume=\dfrac{15}{0.789}$

$\\ \bull\tt\dashrightarrow Volume=19.01mL$

3 0

3 years ago

Ren runs a hamburger stand and needs to clean up a season’s worth of grease buildup on the range hood over his griddle. explain

baherus [9]

Grease cleanerrrrrrr

7 0

4 years ago