an airplane travels down a runway for 4.0 seconds with an acceleration of 9.0 m/s what is its change in velocity during this time


Answer 1
Answer: Given: Time t = 4.0 seconds

           acceleration a = 9.0 m/s²
           Initial Velocity Vi = 0

Required: Change in velocity Vf = ?F

Formula: a = Vf - Vi/t

               Vf = Vi +at

               Vf = 0 m/s + (9.0 m/s²)(4.0 s)

               Vf = 36 m/s

Answer 2
Answer: Acceleration is given in the units of meters per second per second (m/s^2). Thus if the airplane is experiencing a constant acceleration of 9 m/s^2 for a known time period of 4 seconds, its total increase in velocity can be found by multiplying 9 m/s^2 * 4s to yield a velocity increase over the period of 36 m/s.

Related Questions


Which statement correctly defines ethics? A .a set of correct procedures
B. a set of moral values
C.a set of limits on which research options to pursue
D. a set of assumptions generally accepted as true



B. a set of moral values


Ethics is a set of moral values which usually applies in an institution. It refers to the proper and standard practices in which things should be done without infrigering on people's right or values.

Ethical practices are very core to the workings of organisations and institutional settings. It is widely believed that ethics has a deep root in morals and they greatly overlap in ideologies.

B. a set of moral values


Ethics are basically conduction norms that people must follow and that distinguishes people’s good and bad behavior. These ethics should be followed in every field of life be it day to day life or in science doing anything should have certain moral values included in it. So in the question the correct answer would be a set of moral values which people should follow so that it doesn't harm any other person or living being.


Imagine that you are driving up a mountain on a very curvy road at night when the air is very still and not moving. The air temperature is getting colder and colder as you drive up the mountain. Which of the following best describes what happened to the air temperature?



Diathermy and atmospheric pressure


When the energy from the Sun comes to the Earth, it hits first the atmosphere, but the air contained is almost unaffected by it because the molecules are not tight enough to absorb its incoming energy.

Later on, the sunlight reaches the soil, thus absorbing part of the energy and reflecting the rest. Because of this reflection, the air near to the ground begins to heat through convection and as it gains height the air pressure (thus the air molecules begin to separate more from each other) decreases and the energy transfer to them is more difficult. As a result, as you gain height, the air temperature decreases at a rate of 6.8 ºC every 1,000 meters.


A mass of 20.0 kg is attached to a spring that is hanging vertically. The spring stretches .230 m. What is the spring constant?


Given: Mass m = 20.0 Kg;    Displacement  x = 0.230 m

Required:  Spring constant  k = ?

Formula:  F = kx

                k = F/x

                k = (20.0 Kg)(9.8 m/s²)/0.230 m

                k = 852.17 N/m


Two hockey pucks with mass 0.1 kg slide across the ice and collide. Before the collision, puck 1 is going 15 m/s to the east and puck 2 is going 12 m/s to the west. After the collision, puck 2 is going 15 m/s to the east. What is the velocity of puck 1?


After the collision, the velocity of puck 2 can be calculated as below,

From the conservation of momentum, the formula during a collision is given by: m1v1 + m2v2 = m1v'1 + m2v'2.

0.1 *15 + 0.1* 12 = 0.1* x + 0.1* 15

1.5 + 1.2 = x + 1.5

2.7 = x +1.5

X = 1.2

What is collision ?

"Collision, also called impact, in physics, the sudden, forceful coming together in direct contact of two bodies, such as, for example, two billiard balls, a golf club and a ball, a hammer and a nail head, two railroad cars when being coupled together, or a falling object and a floor. "

Know more about collision here



Current enters a circuit at a: 1.positive terminal
2.negative terminal
3.low potential side


It would be the negative terminal ofc

Which theory was revised to obtain the theory of plate tectonics? Continental Drift Theory

Mid-Atlantic Ridge Theory

Pangea Theory

Seafloor Spreading Theory




Continental Drift Theory

You drop a 0.375 kg ball from a height of 1.37 m. It hits the ground and bounces up again to a height of 0.67 m. How much energy did it lose in the bounce?


2.57 joule energy lose in the bounce .


when ball is the height of 1.37 m from the ground  it has some gravitational potential energy with respect to hits the ground  

Formula for gravitational potential energy given by  

Potential Energy = mgh

Where ,

m = mass  

g = acceleration due to gravity  

h = height

Potential energy when ball hits the ground

m= 0.375 kg

h = 1.37 m

g = 9.8 m/s²

Potential Energy = 5.03 joule

Potential energy when ball bounces up again

h= 0.67 m

Potential Energy = 2.46 joule

Energy loss = 5.03 - 2.46 = 2.57 joule

2.57 joule energy lose in the bounce


A student pushes a box across a rough horizontal floor. If the amount of work done by the student on the box is 100 J and the amount of energy dissipated by friction is 40 J, what is the change in kinetic energy of the box





friction is the opposition to the motion of an object. Before a body can be set in motion, part of the energy or work-done must be used to overcome friction.

While kinetic energy is the energy associated with a body due to its motion.

Since friction tends to oppose the motion of a body,when a body start to move, some of the energy applied to the body to cause its motion is converted to heat due to friction.

Hence if a work-done of 100J is applied to a body that requires 40J of the work to overcome friction, the total change in the kinetic energy can be expressed as


Formula of relative displacement​


what is the question?

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