1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
den301095 [7]
3 years ago
12

meg runs a 10-km race in 45 minutes (0.75 hours). what was her speed in kilometers per hour ? a. 7.5 km/hr b. 4.5 km/hr c. 13 km

/hr d. 22 km/hr
Physics
1 answer:
cricket20 [7]3 years ago
3 0
The answer would be C.
You might be interested in
A student wearing frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 45 N. How f
kiruha [24]
Work is obtained by multiplying the force and the object's displacement. The force and displacement and force should be in the same direction in order to have work. 
                                      W = F x d
                                     d = W / F
Substituting the known values,
                                     d = 352 J / 45 N = 7.82 m
Thus, the displacement of the student is 7.82 m. 
8 0
4 years ago
At which temperature do the lattice and conduction electron contributions to the specific heat of Copper become equal.
sp2606 [1]

Answer:

At 3.86K

Explanation:

The following data are obtained from a straight line graph of C/T plotted against T2, where C is the measured heat capacity and T is the temperature:

gradient = 0.0469 mJ mol−1 K−4 vertical intercept = 0.7 mJ mol−1 K−2

Since the graph of C/T against T2 is a straight line, the are related by the straight line equation: C /T =γ+AT². Multiplying by T, we get C =γT +AT³ The electronic contribution is linear in T, so it would be given by the first term: Ce =γT. The lattice (phonon) contribution is proportional to T³, so it would be the second term: Cph =AT³. When they become equal, we can solve these 2 equations for T. This gives: T = √γ A .

We can find γ and A from the graph. Returning to the straight line equation C /T =γ+AT². we can see that γ would be the vertical intercept, and A would be the gradient. These 2 values are given. Substituting, we f ind: T =

√0.7/ 0.0469 = 3.86K.

4 0
3 years ago
A wire that has a resistance of 1Ω is to be built from an aluminum block of volume 1 cm3
alina1380 [7]

Answer:

  L = 5,955 m

Explanation:

For this exercise we must use the relation

        R = ρ L / A

where R is the resistance that indicates that it is 1 Ω, the resistivity is taken from the tables ρ = 2.82 10⁻⁸ Ω m, L is the length of the wire and A is the cross section.

As it indicates to us in volume of aluminum to use we divide the two terms by the length

    R / L = ρ L / (A L)

the volume of a body is its area times its length, therefore

  R / L = ρ L / V

  R = ρ L² / V

we clear the length of the wire

   L = √ R V /ρ

we reduce the volume to SI units

   v = 1 cm³ (1m / 10² cm)³ = 1 10⁻⁶ m

let's calculate

   L = √ (1  1  10⁻⁶ / 2.82 10⁻⁸)

   L = √ (0.3546 10²)

   L = 5,955 m

5 0
3 years ago
What is the force needed to accelerate a wagon with a mass of 10 kg at a rate
Mashutka [201]

Answer:

B

Explanation:

Remember:

<u>F = m * a </u>

 =  10 * 2  = 20 N

6 0
2 years ago
Read 2 more answers
Which of the following is an example of potential energy?
tigry1 [53]
The answer is b because it’s something being stretched and it
7 0
3 years ago
Read 2 more answers
Other questions:
  • slader A uniform cylindrical grinding wheel of mass 50.0 kg and diameter 1.0 m is turned on by an electric motor. The friction i
    13·1 answer
  • A coin completes 18 spins in 12 seconds. The centripetal acceleration of the edge of the coin is 2.2 m/s2. The radius of the coi
    8·2 answers
  • The weight of an object on Earth is 350 newtons. On Mars, the same object would weigh 134 newtons. What is the acceleration due
    14·2 answers
  • The angular position of objects as a function of time is given, where a, b, and care constants. In which of these cases is the a
    6·1 answer
  • Which layer of the sun is seen during a total solar eclipse?
    13·1 answer
  • Explain how fusion and fission are similar to and different from each other. Thanks.
    13·2 answers
  • How are metal bridges built to cope with changes of temperature?
    9·1 answer
  • Reread the different bottle properties found underlined at the top of the first page. Which of the two properties tested is more
    7·2 answers
  • Why would a rocket fall vertically downwards if it was launched vertically upwards​
    11·1 answer
  • Which of Kepler's laws helps you compare the velocities of different planets?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!