Why do planets speed up as they get closer to the sun?:

At an instant a traffic light turns green an automobile that has been waiting at an intersection of the road accelerates with 5m

joja [24]

1) The car overtakes the truck at a distance of 160 m far from the intersection.

2) The velocity of the car is 40 m/s

Explanation:

1)

The car is travelling with a constant acceleration starting from rest, so its position at time t (measured taking the intersection as the origin) is given by

$x_c(t) = \frac{1}{2}at^2$

where

$a=5 m/s^2$ is the acceleration

t is the time

On the other hand, the truck is travelling at a constant velocity, therefore its position at time t is given by

$x_t(t) = vt$

where

v = 20 m/s is the velocity of the truck

t is the time

The car overtakes the truck when the two positions are the same, so when

$x_c(t) = x_t(t)\\\frac{1}{2}at^2 = vt\\t=\frac{2v}{a}=\frac{2(20)}{5}=8 s$

So, after a time of 8 seconds. Therefore, the distance covered by the car during this time is

$x_c(8) = \frac{1}{2}(5)(8)^2=160 m$

So, the car overtakes the truck 160 m far from the intersection.

2)

The motion of the car is a uniformly accelerated motion, so the velocity of the car at time t is given by the suvat equation

$v=u+at$

where

v is the velocity at time t

u is the initial velocity

a is the acceleration

For the car in this problem, we have:

u = 0 (it starts from rest)

$a=5 m/s^2$

And we know that the car overtakes the truck when

t = 8 s

Substituting into the equation,

$v=0+(5)(8)=40 m/s$

Learn more about accelerated motion:

brainly.com/question/9527152

brainly.com/question/11181826

brainly.com/question/2506873

brainly.com/question/2562700

#LearnwithBrainly

8 0

3 years ago

Bare free charges do not remain stationary when close together. To illustrate this, calculate the acceleration of two isolated p

Marta_Voda [28]

Answer:

Acceleration, $a=9.91\times 10^{15}\ m/s^2$

Explanation:

It is given that,

Separation between the protons, $r=3.73\ nm=3.73\times 10^{-9}\ m$

Charge on protons, $q=1.6\times 10^{-19}\ C$

Mass of protons, $m=1.67\times 10^{-27}\ kg$

We need to find the acceleration of two isolated protons. It can be calculated by equating electric force between protons and force due to motion as :

$ma=\dfrac{kq^2}{r^2}$

$a=\dfrac{kq^2}{mr^2}$

$a=\dfrac{9\times 10^9\times (1.6\times 10^{-19})^2}{1.67\times 10^{-27}\times (3.73\times 10^{-9})^2}$

$a=9.91\times 10^{15}\ m/s^2$

So, the acceleration of two isolated protons is $9.91\times 10^{15}\ m/s^2$ . Hence, this is the required solution.

3 0

3 years ago

Pls help :(( I need help!! Its physics! motion and forces!

Delvig [45]

Answer: Pedaling your bike : acceleration :: applying the brakes : inertia.

The reason I think this to be the answer to the analogy is because there is energy and work used in both processes (and the unit focuses on forces); gravity is constant and does not change whether one pedals or applies brakes. And I do not think it's deceleration, as deceleration tends to equate to acceleration within the physics perspective.

Edit: I should also add that since you clarified that your unit is motion and forces, Newtons 1st law is the law of inertia. The way to change an objects motion for it to slow down is by applying an additional force. That resistance the bike experiences to slow is the process of inertia. Inertia happens in order to accelerate an object (either by slowing it down, or speeding it up): i.e., the resistance to change.

8 0

2 years ago

Which graph below represents how the velocity of the sphere changes over time when falling with constant acceleration?

Amiraneli [1.4K]

Graph B represents the velocity of the sphere changes over time when falling with constant acceleration.

Acceleration is the measure of how quickly a body's velocity varies with regard to time, and constant acceleration occurs when a body's velocity changes proportionately over a period of time, or at a constant rate. It measures in m/s2.

It is claimed that a body has continual positive acceleration when it begins to move with an initial velocity of zero and gradually increases to a positive value over time.

Constant positive acceleration is demonstrated by a ball falling freely in a vertical direction.

To know more about constant acceleration. visit : brainly.com/question/9754169

#SPJ1

4 0

1 year ago

1.A heater supplies 500kj (500,000J) over 10 minutes.

ohaa [14]

Umm... I think I saw this question somewhere else answered.... You should look for it.

4 0

3 years ago