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
PolarNik [594]
3 years ago
5

Người ta ném một hòn bi theo phương ngang với vận tốc ban đầu là 15m/s và nó rơi xướng đất sau 4s. Bỏqua sức cản của không khí v

à lấy g=10 m/s2. Hỏi hòn bi được ném từđộcao nào và tầm xa của nó là bao nhiêu?
Physics
1 answer:
Juliette [100K]3 years ago
5 0

Answer:

h = 80m L = 60m

Explanation:

Độ cao Ng ta ném hòn bi là

t=\sqrt{\frac{2h}{9}} => 4^2 = \frac{2h}{10}

h= 80m

Tầm bay xa:

L= Vo . t = 15.4 = 60m

Chúc học tốt nghen

You might be interested in
a skier starts from rest and skis down a 82 meter tall hill labeled h1, into a valley and staught back up another 35 meter hill(
horrorfan [7]

Answer:

She is going at 30.4 m/s at the top of the 35-meter hill.    

Explanation:

We can find the velocity of the skier by energy conservation:

E_{1} = E_{2}

On the top of the hill 1 (h₁), she has only potential energy since she starts from rest. Now, on the top of the hill 2 (h₂), she has potential energy and kinetic energy.

mgh_{1} = mgh_{2} + \frac{1}{2}mv_{2}^{2}    (1)

Where:

m: is the mass of the skier

h₁: is the height 1 = 82 m

h₂: is the height 2 = 35 m

g: is the acceleration due to gravity = 9.81 m/s²  

v₂: is the speed of the skier at the top of h₂ =?

Now, by solving equation (1) for v₂ we have:

v_{2}^{2} = \frac{2mg(h_{1} - h_{2})}{m}  

v_{2} = \sqrt{2g(h_{1} - h_{2})} = \sqrt{2*9.81 m/s^{2}*(82 m - 35 m)} = 30.4 m/s    

Therefore, she is going at 30.4 m/s at the top of the 35-meter hill.

I hope it helps you!  

6 0
2 years ago
An athlete with mass m running at speed v grabs a light rope that hangs from a ceiling of height H and swings to a maximum heigh
-Dominant- [34]

Answer:

d) The 2 athletes reach the same height, because the athletes run with the same speed.

Explanation:

In the whole process , kinetic energy is converted into potential energy .

1/2 m v² = mgh

v² = 2gh

h = v² / 2g

In this expression we see that height attained does not depend upon mass of the object . At the same time it also makes it clear that it depends upon velocity . As the velocity in both the cases are same , height attained by both of them will be same. Hence option d ) is correct.

7 0
3 years ago
1. The whole world is __________________ with rocks.
ArbitrLikvidat [17]
I got it keep it bucks worth u this it tooooo muchhhhhhh
4 0
2 years ago
Read 2 more answers
Which example describes constant acceleration due ONLY to a change in direction?
Brut [27]

'Traveling around a circular track' can be a description of constant
acceleration due only to changes in direction.  But if it is, then the
progress around the circular track must be at constant speed.

5 0
3 years ago
Read 2 more answers
How much tension must a cable withstand to accellerate a 1400 kg car vertically upward at 0.70 m/s^2
MariettaO [177]

Answer:

Below

Explanation:

The cars upward accel adds to the gravity accel (think about how suddenly heavy you feel when the elevator starts to move upward)

F = tension = ma

                   = 1400 * ( .7 + 9.81) = 14714 N

7 0
1 year ago
Other questions:
  • A rocket takes off from Earth and reaches a speed of 105 m/s in 18.0 s. If the exhaust speed is 1,200 m/sand the mass of fuel bu
    13·1 answer
  • A 70 kg runner exerts a force of 35n. what is the acceleration of the runner
    7·1 answer
  • What is the gravitational potential energy of a 150 kg object suspended 5m above the Earth's surface
    13·1 answer
  • Protein synthesis is vital for cell growth and metabolism. Transcription and translation are known as the central dogma of biolo
    8·2 answers
  • How many kisses is 50 hectokisses?<br><br> What would you be if you earn a megabuck year?
    5·2 answers
  • Calculate the force on an object that has a mass of 12kg and an acceleration of 4m/s2.
    5·2 answers
  • Two clowns are launched from the same spring-loaded circus cannon with the spring compressed the same distance each time. Clown
    6·1 answer
  • The greater the mass is in an object, the higher resistance to a change in movement the object will have. Please select the best
    6·1 answer
  • What kind of electromagnetic waves are used by an FM radio?.
    8·1 answer
  • One of the reasons you love your home is because every side of your home faces South. One day, while talking on the phone, you h
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!