All categories

3 years ago

A car starts from rest and undergoes an acceleration of 4.0 m/s/s for a time of 5.0 s. What is the final velocity of the car?

Physics

1 answer:

Kruka [31]3 years ago

7 0

Answer:

20m/s

Explanation:

acceleration=final velocity-initial velocity/time

4.0m/s²=v m/s-0m/s/5.0sec

5.0sec×4.0m/s²=v m/s-0m/s×5.0m/s/5.0m/s

20m/s=v

You might be interested in

After an avalanche, a huge block of stone slid down a mountain and landed in the middle of a road. People in the nearby town had

jeka94

Answer:

Option (C)

Explanation:

From Newton's law of inertia, an object at rest tends to be at rest until there is an external force applied to it.

In the given question, the rock block that fell on the road due to the avalanche contains high mass and high inertia. Due to which the block was not able to move aside. <u>The amount of energy required to push the block aside should be more than the mass of the block</u>. So the block has high inertia value and it will need more force than its inertia value in order to move the block of rock towards the side of the road.

Thus, the correct answer is option (C).

4 0

3 years ago

A rocket in deep space has an empty mass of 150 kg and exhausts the hot gases of burned fuel at 2500 m/s. It is loaded with 600

3241004551 [841]

Answer:

$v(10\,s) \approx 775.387\,\frac{m}{s}$

$v(20\,s)\approx 1905.350\,\frac{m}{s}$

$v(30\,s) \approx 4023.595\,\frac{m}{s}$

Explanation:

The speed of the rocket is given the Tsiolkovsky's differential equation, whose solution is:

$v (t) = v_{o} - v_{ex}\cdot \ln \frac{m}{m_{o}}$

Where:

$v_{o}$ - Initial speed of the rocket, in m/s.

$v_{ex}$ - Exhaust gas speed, in m/s.

$m_{o}$ - Initial total mass of the rocket, in kg.

$m$ - Current total mass of the rocket, in kg.

Let assume that fuel is burned linearly. So that,

$m(t) = m_{o} + r\cdot t$

The initial total mass of the rocket is:

$m_{o} = 750\,kg$

The fuel consumption rate is:

$r = -\frac{600\,kg}{30\,s}$

$r = -20\,\frac{kg}{s}$

The function for the current total mass of the rocket is:

$m(t) = 750\,kg - (20\,\frac{kg}{s} )\cdot t$

The speed function of the rocket is:

$v(t) = - 2500\,\frac{m}{s}\cdot \ln \frac{750\,kg -(20\,\frac{kg}{s} )\cdot t}{750\,kg}$

The speed of the rocket at given instants are:

$v(10\,s) \approx 775.387\,\frac{m}{s}$

$v(20\,s)\approx 1905.350\,\frac{m}{s}$

$v(30\,s) \approx 4023.595\,\frac{m}{s}$

7 0

3 years ago

Gravity is a force. Gravity is also an example of __________________. . . A.. a theory. . B.. an established procedure. . C.. a

MissTica

The correct answer to this question is C - Gravity is a force. Gravity is also an example of a universal law. Well, according to Isaac Newton, anyway. According to Newton's Law of Universal Gravitation, 'every point mass attracts every single point mass by a force pointing along the line intersecting both paths.'
<span />

7 0

3 years ago

Friction is just hot air rubbing off the inevitable force of solid <br> prove me wrong

Lorico [155]

Answer:

friction is when two objects tough with force basically. when an object is rubbed against something. when an object comes in contact with something else. or ig u can call it hot air rubbing off the inevitable force lol that works too , bud

whatever helps u rememeber

3 0

3 years ago

When listening to tuning forks of frequency 256 Hz and 260 Hz, one hears the following number of beats per second. (A) 0 (B) 2 (

Degger [83]

Answer:

Explanation:

As we know that the no of beats can be calculated as.

No. of beats is equal to difference in the tuning forks frequencies.

So,

$n= \nu _{1}- \nu _{2}$ .

Substitute the values of frequencies of 2 tuning forks in the above equation.

$n=(260 Hz-256 Hz)\\n=4$

Therefore the number of beats per second will be hear by the observer is 4 beats per second.

3 0

3 years ago