All categories

3 years ago

a car is traveling north on the interstate. They cover 645 miles in 9 hours. What is the car's average velocity ?

Physics

2 answers:

mojhsa [17]3 years ago

8 0

Answer:

71.6 mph

Explanation:

you would do 645 divided by 9 which would give you 71.6

kow [346]3 years ago

7 0

71.66 miles per hour

You might be interested in

A cylinder fitted with a piston exists in a high-pressure chamber (3 atm) with an initial volume of 1 L. If a sufficient quantit

Bess [88]

Answer:

C. 85%

Explanation:

A cylinder fitted with a piston exists in a high-pressure chamber (3 atm) with an initial volume of 1 L. If a sufficient quantity of a hydrocarbon material is combusted inside the cylinder to produce 1 kJ of energy, and if the volume of the chamber then increases to 1.5 L, what percent of the fuel's energy was lost to friction and heat?

A. 15%

B. 30%

C. 85%

D. 100%

work done by the system will be

W=PdV

p=pressure

dV=change in volume

3tam will be changed to N/m^2

3*1.01*10^5

W=3.03*10^5*(1.5-1)

convert 0.5L to m^3

5*10^-4

W=3.03*10^5*5*10^-4

W=152J

therefore

to find the percentage used

152/1000*100

15%

100%-15%

85% uf the fuel's energy was lost to friction and heat

6 0

3 years ago

A mass of 1.03 kilograms is placed on a horizontal frictionless surface against an uncompressed spring with spring constant 861.

Lelechka [254]

Answer:

5.522 m

Explanation:

Data provided:

Mass, m = 1.03 kg

spring constant, k = 861.1 N/m

Distance by which the spring is compressed, x = 0.36

Thus,

the energy stored in the spring = $\frac{1}{2}kx^2$

on substituting the values, we get

the energy stored in the spring = $\frac{1}{2}\times861.1\times0.36^2$

now,

by the conservation of energy, we have

Potential energy gained by the mass = Energy gained by the spring

mgh = $\frac{1}{2}\times861.1\times0.36^2$

where,

g is the acceleration due to the gravity

h is the maximum height reached by the mass before falling

on substituting the values in the above relation, we get

1.03 × 9.81 × h = $\frac{1}{2}\times861.1\times0.36^2$

h = 5.522 m

8 0

3 years ago

Viking I, the first spacecraft to land on Mars, travelled 7.00 x 108 km in 303 days. Calculate its average speed, in kilometres

vesna_86 [32]

Answer:

hamburger

Explanation:

taste good

5 0

2 years ago

A boat is headed with a velocity of 18 meters/second toward the west with respect to the water in a river. If the river is flowi

artcher [175]

Answer:

20.5

Explanation:

in this case, the two vectors are in the same direction, so they simply add:

total motion = 18m/s + 2.5m/s = 20.5m/s to the west

8 0

3 years ago

A 50.0 mg sample of an unknown radioactive substance was placed in storage and its mass measured periodically. After 19.7 days,

PilotLPTM [1.2K]

<h2>Answer: 4.928 days </h2><h2 />

Explanation:

This problem can be solved using the <u>Radioactive Half Life Formula: </u>

<u></u>

$A=A_{o}.2^{\frac{-t}{h}}$ (1)

Where:

$A=3.13mg$ is the final amount of the material

$A_{o}=50mg$ is the initial amount of the material

$t=19.7days$ is the time elapsed

$h$ is the half life of the material (the quantity we are asked to find)

Knowing this, let's substitute the values and find $h$ from (1):

$3.13mg=(50mg)2^{\frac{-19.7days}{h}}$ (2)

$\frac{3.13mg}{50mg}=2^{\frac{-19.7days}{h}}$ (3)

Applying natural logarithm in both sides:

$ln(\frac{3.13mg}{50mg})=ln(2^{\frac{-19.7days}{h}})$ (4)

$-2.77=-\frac{19.7days}{h}ln(2)$ (5)

Clearing $h$ :

$h=\frac{-19.7days}{-2.77}(0.693)$ (6)

Finally:

$h=4.928days$

6 0

3 years ago