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
My name is Ann [436]
2 years ago
13

Please help me with this question guys.

Physics
1 answer:
katen-ka-za [31]2 years ago
7 0

Answer:

<em>The average speed is 22.2 km/h</em>

Explanation:

<u>Average Speed</u>

Given an object travels a total distance d and took a total time t, then the average speed is:

\displaystyle \bar v=\frac{d}{t}

The mailman first drives d1=7 km at v1=15 km/h. The time taken to drive is:

\displaystyle t1=\frac{d1}{v1}=\frac{7}{15}=0.467\ h

Then he drives d2=7 km at v2=43 km/h taking a time of:

\displaystyle t2=\frac{d2}{v2}=\frac{7}{43}=0.163\ h

The total time is

t=0.467 h + 0.163 h = 0.63 h

The total distance is

d = 7 km + 7 km = 14 km

The average speed is:

\displaystyle \bar v=\frac{14}{0.63}=22.2\ km/h

The average speed is 22.2 km/h

You might be interested in
What causes an object to move, change direction or change speed?
Wittaler [7]
I believe it would be an unbalanced force. Because the forces are unbalanced, one side is stronger and, therefore, the object will move.
7 0
3 years ago
Read 2 more answers
The function of a capacitor in an electric circuit is to
jok3333 [9.3K]

Answer: B. store electric charges.

Explanation: I JUST TOOK THE PF EXAM AND I GOT IT CORRECT!!!!

7 0
3 years ago
A 3858 N piano is to be pushed up a(n) 3.49 m frictionless plank that makes an angle of 31.6 ◦ with the horizontal. Calculate th
uranmaximum [27]
The work done will be equal to the potential energy of the piano at the final position

P.E=m.g.h

.consider the plank the hypotenuse of the right triangle formed with the ground
.let x be the angle with the ground=31.6°
.h be the side opposite to the angle x (h is the final height of the piano)
.let L be the length of the plank

sinx=opposite side / hypotenuse
= h/L

then h=L.sinx=3.49×sin31.6°=0.638m

weight w=m.g
m=w/g=3858/10=385.8kg

Consider Gravity g=10m/s2

then P.E.=m.g.h=385.8kg×10×0.638=2461.404J

then Work W=P.E.=2451.404J
8 0
3 years ago
Read 2 more answers
What's the mass show the work?
Alja [10]
You do this one just like the other one that I just solved for you.

For this one ...

The density of the object is 2.5 gm/cm³.
We know that every cm³ of it we have contains 2.5 gm of mass.
We have to find out how many cm³ we have.

The question tells us:  We have  2.0 cm³.

Each cm³ of space that the object occupies contains 2.5 gm of mass.

So the 2.0 cm³ that we have contains (2 x 2.5 gm) = 5 gms.
That's the mass of our object.
6 0
3 years ago
Who was the first president of kenya​
Damm [24]

Answer: Jomo Kenyatta

Explanation: Jomo Kenyatta was an anti-colonial activist and politician and was the first Prime Minister of Kenya. He then served as president of the country from 1964 to his death in 1978

7 0
3 years ago
Read 2 more answers
Other questions:
  • What happened the year that isaac newton was born
    10·2 answers
  • A small amber bead with a mass of 12.6 g and a charge of −0.646 µC is suspended in equilibrium above the center of a large, hori
    10·1 answer
  • The yield strength for an alloy that has an average grain diameter of 4.5 x 10-2 mm is 109 MPa. At a grain diameter of 6.8 x 10-
    10·1 answer
  • The total mass of the wheelbarrow and the road is 80 kg calculate the weight of the wheelbarrow and the road
    12·1 answer
  • Uma wants to recreate the discovery of superconductivity. Which describes the materials needed?
    10·2 answers
  • Please round to three sig fig
    8·1 answer
  • Why is a spectrum of colors produced when white light passes through a prism?
    8·1 answer
  • Which of the following conditions would always result in a net force of 0N?
    14·2 answers
  • A car moving at 60 mph slams on its brakes to stop before hitting a deer. Another identical car traveling at 60 mph slows to a s
    11·1 answer
  • The speed that a tsunami can travel is modeled by the equation , where s is the speed in kilometers per hour and d is the averag
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!