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
Anna [14]
3 years ago
9

In a 4.0-kilometer race, a runner completes the first kilometer in 5.9 minutes, the second kilometer in 6.2 minutes, the third k

ilometer in 6.3 minutes, and the final kilometer in 6.0 minutes. The average speed of the runner for the race is approximately
A) 0.16 km/min B) 0.33 km/min

C) 12 km/min D) 24 km/min
Physics
1 answer:
Svetlanka [38]3 years ago
3 0

As per the question the total distance is given as 4 km.

We are asked to calculate the average speed.

The time taken by the body to travel each kilometre are 5.9 min,6.2 min.,6.3min. and 6 min. respectively.

The average speed of a body is defined as the ratio of total distance travelled by the body to the total time.

Mathematically the average speed is written as _

V= Total distance/Total time

i.e V = S/T

Where S is the total distance travelled and T is the total time

Here total distance (S)= 4 km

The total time T= (5.9+6.2 +6.3+ 6.0 )minutes

=24.4 min.

Hence average speed V = 4 km/24.4 min

= 0.16 km/min.

Hence the correct option is A .


You might be interested in
dam is used to block the passage of a river and to generate electricity. Approximately 58.4 x 103 kg of water falls each second
mrs_skeptik [129]

Answer:

8.049 MW

Explanation:

The expression for gravitational potential energy is given as

Ep = mgh............. Equation 1

Ep = gravitational potential energy, m = mass of water, h = height, g = acceleration due to gravity.

Given: m = 58.4×10³ kg, h = 20.1 m, g = 9.81 m/s²

Substitute into equation 1

Ep =  58.4×10³(20.1)(9.81)

Ep = 1.6098×10⁷ J.

If one half the gravitational potential energy of the water were converted to electrical energy

Electrical energy = Ep/2

Electrical energy = (1.6098×10⁷)/2

Electrical energy = 8.049×10⁶ J

In one seconds,

The power generated = 8.049×10⁶ W

Power generated = 8.049 MW

3 0
3 years ago
A 560-g squirrel with a surface area of 930cm2 falls from a 5.0-m tree to the ground. Estimate its terminal velocity. (Use a dra
bija089 [108]

Explanation:

Terminal velocity is given by:

v_t=\sqrt{\frac{2mg}{\rho C_dA}}

Here, m is the mass of the falling object, g is the gravitational acceleration,  C_d is the drag coefficient, \rho is the fluid density through which the object is falling, and A is the projected area of the object. in this case the projected area is given by:

A=\frac{A_s}{2}=\frac{930cm^2}{2}=465cm^2\\465cm^2*\frac{1m^2}{10^4cm^2}=0.0465m^2\\560g*\frac{1kg}{10^3g}=0.56kg

Recall that drag coefficient for a horizontal skydiver is equal to 1 and air density is 1.28\frac{kg}{m^3}.

v_t=\sqrt{\frac{2(0.56kg)(9.8\frac{m}{s^2})}{(1.28\frac{kg}{m^3}(1)(0.0465m^2)}}\\v_t=13.58\frac{m}{s}

Without drag contribution the motion of the person is an uniformly accelerated motion, thus:

v_f^2=v_o^2+2gh\\v_f=\sqrt{2gh}\\v_f=\sqrt{2(9.8\frac{m}{s^2})(5m)}\\v_f=9.9\frac{m}{s}

7 0
3 years ago
A 0.l ‑kilogram block is attached to an initially unstretched spring of force constant k = 40 N/m as shown right. The block is d
GalinKa [24]

Answer:

The maximum potential energy of the system is 0.2 J

Explanation:

Hi there!

When the spring is stretched, it acquires potential energy. When released, the potential energy is converted into kinetic energy. If there is no friction nor any dissipative forces, all the potential energy will be converted into kinetic energy according to the energy conservation theorem.

The equation of elastic potential energy (EPE) is the following:

EPE = 1/2 · k · x²

Where:

k = spring constant.

x = stretching distance.

The elastic potential energy is maximum when the block has no kinetic energy, just before releasing it.

Then:

EPE = 1/2 · 40 N/m · (0.1 m)²

EPE = 0.2 J

The maximum potential energy of the system is 0.2 J

8 0
3 years ago
An oblique rectangular prism with a square base has a volume of 539 cubic units. The edges of the prism measure 7 by 7 by 14 uni
Gala2k [10]

Answer:

3 units

Solution:

V=539 cubic units

Square base, with edge a=7 units

Slanted edge length: s=14 units

V=Ab h

Ab=49 square units

539 cubic units = (49 square units) h

h= 11 units

s-h=14 units-11 units

s-h=3 units

8 0
3 years ago
Read 2 more answers
A ball is thrown into the air
Alenkinab [10]
And because of gravity it falls back down to the earth.
5 0
3 years ago
Other questions:
  • What is the acceleration of a 10 kg mass pushed by a 5 N force?
    8·2 answers
  • A competitive go-cart driver is traveling at a speed of 32m/s. He sees a caution flag go up and slows down at a rate of -1.5 m/s
    7·1 answer
  • What collides and creates a movement of heat called conduction?
    13·1 answer
  • Is the refractive index constant?
    9·2 answers
  • Kinetic energy is _____.inversely proportional to mass and velocity directly proportional to mass and velocity directly proporti
    6·2 answers
  • A force of 6600 N is exerted on a piston that has an area of 0.010 m2
    12·1 answer
  • Analyze the explanation and identify any false statements. Each statement to be analyzed is identified by a capital letter. A ba
    8·1 answer
  • Complete the wording of the Law of Conservation of Matter and Energy (as defined in the text).
    11·1 answer
  • As thermal energy is added to a sample of water, the kinetic energy of its
    5·1 answer
  • (PLEASE HELP ILL GIVE OUT BRAINLIEST) Mr. Hicks stands on top of the roof and drops water ball oons at passing students. He miss
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!