All categories

3 years ago

A skier has an acceleration of 2.5 m/s2. How long does it take her to come to a complete stop from a speed of 18 m/s?

2 answers:

8 0

A = 2.5 m/s²

since , we have to stop so v = 0 m/s ( final velocity)

u = 18 m/s

t = ?

using ,

⇒ v = u + at

⇒ 0 = 18 + 2.5t

by this we are getting t<0 , since , t cant be -ve , Check your question

aleksandr82 [10.1K]3 years ago

4 0

(Assuming acceleration is -2.5m/s2) 7.2 seconds.

You might be interested in

Someone please help me

bagirrra123 [75]

Oxygen. Plants need water sunlight and CO2 to make their food. They get the carbon and the energy from the CO2 and the sun, and they need water as well. Then they release oxygen

3 0

3 years ago

In a oxidation-reduction reaction, the oxidizing agent always undergoes reduction.

Free_Kalibri [48]

In a oxidation-reduction reaction, the oxidizing agent always undergoes reduction.

TRUE.

6 0

3 years ago

Read 2 more answers

What is harmonic motion

Tanzania [10]

Answer: NNOOOOOOOOOOOOOOOOOOONONONO

Explanation: simple harmonic motion, in physics, repetitive movement back and forth through an equilibrium, or central, position, so that the maximum displacement on one side of this position is equal to the maximum displacement on the other side. The time interval of each complete vibration is the same. The force responsible for the motion is always directed toward the equilibrium position and is directly proportional to the distance from it. That is, F = −kx, where F is the force, x is the displacement, and k is a constant. This relation is called Hooke’s law.

A specific example of a simple harmonic oscillator is the vibration of a mass attached to a vertical spring, the other end of which is fixed in a ceiling. At the maximum displacement −x, the spring is under its greatest tension, which forces the mass upward. At the maximum displacement +x, the spring reaches its greatest compression, which forces the mass back downward again. At either position of maximum displacement, the force is greatest and is directed toward the equilibrium position, the velocity (v) of the mass is zero, its acceleration is at a maximum, and the mass changes direction. At the equilibrium position, the velocity is at its maximum and the acceleration (a) has fallen to zero. Simple harmonic motion is characterized by this changing acceleration that always is directed toward the equilibrium position and is proportional to the displacement from the equilibrium position. Furthermore, the interval of time for each complete vibration is constant and does not depend on the size of the maximum displacement. In some form, therefore, simple harmonic motion is at the heart of timekeeping.

3 0

2 years ago

"The drawing shows three layers of different materials, with air above and below the layers. The interfaces between the layers a

My name is Ann [436]

Answer:

Angle of incidence that entered material b= 63.1°

Angle of incidence between a and b = 55.9°

Explanation: Using the formular:

n1sintheta1= n2sintheta2

The light ray which enters material B will be

1.4Sin72.8° = 1.5Sin theta

1.3373= 1.5Sintheta

sintheta = 1.3373/1.5

Sin^-1 0.8916 = Theta

63.1 = theta

When the ray hits interface with material a

1.5Sin63.1 = 1.3 Sin theta

1.3374 = 1.3Sin theta

Sintheta= 1.3374/1.3

Sin theta = 1.0877

There will be total reflection off the boundary b c because sin theta exceeded 1 in value.

The equation should be

1.4sin63.1 = 1.4 sin theta

Sin theta=72.8°

When the ray hits air-c boundary:

1.4sin72.8=1.00sin theta

Sin theta=1.3374/1 =1.3374

There is total reflection.

In material a,the ray will:

1.3sin72.8° = 1.00sin theta

There will be total reflection when the ray hits a-b boundary.

1.3sin72.8= 1.5sintheta

Sin theta= 1.2419/ 1.5

Sin theta =0.8279

Theta= Sin^-10.8279= 55.88°

When ray hits c-air boundary

1.4sin63.1= 1.00sintheta

1.2485= sin theta = Toal reflection.

Therefore when the ray of light pass through the layers of material a, b and c the boundary with air on top and bottom will be total reflection.

7 0

3 years ago

The forklift exerts a 1,500.0 N force on the box and moves it 3.00 m forward to the stack. How much work does the forklift do ag

allochka39001 [22]

In order to get the propoerty of work you need to use the following formula
<span>work = force times distance
</span>replacing data you will get:
W = (1.500) (3)
W = 4.500 NM
The answer should be in NM. So it will be 4500 NM againts the force of gravity

4 0

3 years ago