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3 years ago

2. A car with mass 2,500 kg is travelling at 15 m/s. What is the car's kinetic energy?

Physics

1 answer:

BabaBlast [244]3 years ago

7 0

Answer:

c, 280,000J

Explanation:

You should use the equation KE (Kinetic Energy) = $\frac{1}{2} mv^2$

m = 2500

v = 15

KE = $\frac{1}{2} * 2500 * (15)^2\\$

KE = 281250 Joules.

This is consistent with the answer B, as all of the parameters given to you are rounded to 2 significant figures so naturally, the answer should also be rounded to 2 sig figs.

KE = 280,000 J

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The action of two forces. One is a forward force of 1157 N provided by traction between the wheels and the road. The other is a

Pie

Complete question

A 2700 kg car accelerates from rest under the action of two forces. one is a forward force of 1157 newtons provided by traction between the wheels and the road. the other is a 902 newton resistive force due to various frictional forces. how far must the car travel for its speed to reach 3.6 meters per second? answer in units of meters.

Answer:

The car must travel 68.94 meters.

Explanation:

First, we are going to find the acceleration of the car using Newton's second Law:

$\sum\overrightarrow{F}=m\overrightarrow{a}$ (1)

with m the mass , a the acceleration and $\sum\overrightarrow{F}$ the net force forces that is:

$(F-f)$ (2)

with F the force provided by traction and f the resistive force:

(2) on (1):

$(F-f)=ma$

solving for a:

$a=\frac{F-f}{m} =\frac{1157N-902N}{2700kg} =0.094\frac{m}{s^{2}}$

Now let's use the Galileo’s kinematic equation

$Vf^{2}=Vo^{2}+2a\varDelta x$ (3)

With Vo te initial velocity that's zero because it started from rest, Vf the final velocity (3.6) and $\varDelta x$ the time took to achieve that velocity, solving (3) for $\varDelta x$ :

$\varDelta x= \frac{Vf^{2}}{2a} = t= \frac{(3.6\frac{m}{s})^2}{2*0.094\frac{m}{s^{2}}}$

$t=68.94 m$

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3 years ago

What is a metallic bond?<br> Explain in like a simple way please

masya89 [10]

Metallic bond, force that holds atoms together in a metallic substance. ... The atoms that the electrons leave behind become positive ions, and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together.

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3 years ago

Read 2 more answers

A mountain climber increases their height from 200 meters to 400 meters. What affect will this have on their potential energy?

Yanka [14]

Answer:

At 400 m the potential energy of the mountain climber doubled the initial value.

Explanation:

Given;

initial height of the mountain climber = 200 m

final height of the mountain climber, = 400 m

The potential energy of the mountain climber is calculated as;