In the effects of kinetic energy, the slower an object goes, the longer that it will take to bring that object to a stop.

Car A (mass 1100 kg) is stopped at a traffic light when it is rearended by car B(mass 1400 kg). Both cars then slide with locke

viva [34]

Answer:

Part a)

$v_a = 3.94 m/s$

Part b)

$v_b = 3.35 m/s$

Part C)

$v_b = 6.44 m/s$

Part d)

Due to large magnitude of friction between road and the car the momentum conservation may not be valid here as momentum conservation is valid only when external force on the system is zero.

Explanation:

Part a)

As we know that car A moves by distance 6.1 m after collision under the frictional force

so the deceleration due to friction is given as

$a = -\frac{F_f}{m}$

$a = -\frac{\mu mg}{m}$

$a = - \mu g$

now we will have

$v_f^2 - v_i^2 = 2ad$

$0 - v_i^2 = 2(-\mu g)(6.1)$

$v_a = \sqrt{(2(0.13)(9.81)(6.1)}$

$v_a = 3.94 m/s$

Part b)

Similarly for car B the distance of stop is given as 4.4 m

so we will have

$v_b = \sqrt{2(0.13)(9.81)(4.4)}$

$v_b = 3.35 m/s$

Part C)

By momentum conservation we will have

$m_1v_{1i} = m_1v_{1f} + m_2v_{2f}$

$1400 v_b = 1100(3.94) + 1400(3.35)$

$v_b = 6.44 m/s$

Part d)

Due to large magnitude of friction between road and the car the momentum conservation may not be valid here as momentum conservation is valid only when external force on the system is zero.

3 0

3 years ago

If you had an unlimited amount of mass to hang, what would be the range of possible accelerations for the system?

LenaWriter [7]

Answer:

The entire cart/hanging mass system follows the same law, ΣF = ma. This means that plotting force vs. acceleration yields a linear relationship (of the form y = mx).

3 0

2 years ago

A weightlifter lifts a set of weights a vertical distance of 2.00m.If a constant net force of 350 N is exerted on the weights,wh

MrMuchimi

Answer:

W=700 Joule

Explanation:

Physics Work

Is the dot product of the force vector by the displacement vector

$W=\vec F \cdot \vec r$

When both the force and the displacements are pointed in the same direction, the formula reduces to its scalar version

$W=F.d$

The weightlifter is applying a net force of 350 N to lift the weights a distance of 2 m, thus the net work done is

$W=350\ N\ .\ 2\ m=700\ Joule$

4 0

3 years ago

The capacity of one brain area to take over the functions of another damaged brain area is known as brain: (2 points)

Ket [755]

Answer: Plasticity

Explanation: Plasticity is defined as the brain's ability to adapt to changes that may result from damage or birth defects. The adaptation that usually occurs is when affected area of the brain is taken over by healthy functioning cortex.

7 0

3 years ago

Black vultures excel at gliding flight; they can move long distances through the air without flapping their wings while undergoi

GenaCL600 [577]

Answer:

The vulture loses 6.1 m height

Explanation:

Please see the attached figure.

The horizontal distance and the loss of height form a 90º triangle.

The loss of height is the side opposite the given angle (3.5º) and the 100 m horizontal distance is adjacent the angle.

Then, using trigonometric rules:

(1) sin 3.5º = h / hyp

(2) cos 3.5º = distance / hyp

where

h = height lost during the flight.

hyp = hypotenuse of the triangle

Using (2) we can calculate the hypotenuse:

cos 3.5º = 100 m / hyp

hyp = 100 m / cos 3.5º = 100.2 m

with the hypotenuse we can now calculate the loss of height using (1):

sin 3.5º = h / hyp

sin 3.5º = h / 100.2 m

sin 3.5º * 100.2 m = h

h = 6.1 m

( very modest drop in height indeed!)

Download pdf

4 0

3 years ago