All categories

3 years ago

Use newton's laws to find an expression for the net external force acting on the car. ignore air resistance.

1 answer:

4 0

Hi, thank you for posting your question here at Brainly.

Newton's second law of motion can be expressed as Fnet = ma. The next external for acting on, say for example, a moving car are the following:

*weight due to gravity (force down)
*friction force between he road and the car's tires (force opposite the car's direction)

You might be interested in

A 1.5kg cart moves along a track at 0.20m/s until it hits a fixed bumper at the end of the track. Find the average force exerted

DochEvi [55]

Answer:

Net force will be 4.875 N

Explanation:

We have given mass of the cart m = 1.5 kg

Initial velocity of the cart = 0.2 m/sec

And final velocity of the car = - 0.125 m/sec ( Negative direction is due to opposite direction )

Instant of time $\Delta t=0.1sec$

Change in momentum is given by

$\Delta P=1.5\times (0.2-(-0.125))=1.5\times 0.325=0.4875kgm/sec$

Now force is given by

$F=\frac{\Delta P}{\Delta t}=\frac{0.4875}{0.1}=4.875N$

Net force will be 4.875 N

6 0

3 years ago

A train 471 m long is moving on a straight track with a speed of 75.1 km/h. The engineer applies the brakes at a crossing, and l

hram777 [196]

Answer:

$t = 37.6 s$

Explanation:

As we know that train is initially moving with the speed

$v_i = 75.1 km/h$

now we know that

$v_i = 20.86 m/s$

now the final speed of the train when it crossed the crossing

$v_f = 15 km/h$

$v_f = 4.17 m/s$

now we can use kinematics here

$v_f^2 - v_i^2 = 2 a d$

$4.17^2 - 20.86^2 = 2 a(471)$

$a = -0.44 m/s^2$

Now the time to cross that junction is given as

$v_f - v_i = at$

$4.17 - 20.86 = a(-0.44)$

$t = 37.6 s$

4 0

3 years ago

A 1300 kg car moving at 20 m/s and a 900 kg car moving at 15 m/s in precisely oppositedirections participate in a head-on crash.

miskamm [114]

Given

Car 1

m1 = 1300 kg

v1 = 20 m/s

m2 = 900 kg

v2 = -15 m/s

(Negative sign shows that direction of car 2 is opposite to car 1)

Procedure

As per the conservation of linear momentum, "The total momentum of the system before the collision must be equal to the total momentum after the collision". And this applies to the perfectly inelastic collision as well. Then the expression is,

$\begin{gathered} m_1v_1+m_2v_2=(m_1+m_2)v \\ v=\frac{m_1v_1+m_2v_2}{m_1+m_2} \\ v=\frac{1300\operatorname{kg}\cdot20m/s-900\operatorname{kg}\cdot15m/s}{1300\operatorname{kg}+900\operatorname{kg}} \\ v=5.681m/s \end{gathered}$

Thus, we can conclude that the speed and direction of the cars after the impact is 5.68 m/s towards the first car.

5 0

1 year ago

It is epistemically possible that a completed physics might include which of the following propositions? O Souls and other spiri

ohaa [14]

Answer:

option D.

Explanation:

The correct answer is option D.

At present the knowledge of physics does not includes the study related to souls , other spiritual substance.

Physics does not give the answers of question like God created universe , matter is unreal, etc.

So, there might will be possibility that in future complete physics will give the answer of all these questions i.e. correct answer is All of the above.

3 0

3 years ago

How can a organization encourage total person development among their employees.

Sedbober [7]

Answer:

Paying for employees seminars and workshops related to their careers

Explanation:

To motivate personal development among employees, several things can be done. Among them, giving employees chance to present their own solutions to problems, exposing the employees to several global challenges and how to handle them, paying for employees seminars and workshops related to their own careers for professional development among other things.

8 0

3 years ago