2. Jak myślisz, dlaczego w naszym słowniku bez problemu odnajdziemy następujące wyrażenia

The graph represents velocity over time. What is the acceleration? –0.4 m/s2 –0.2 m/s2 0.2 m/s2 0.4 m/s2

Olenka [21]

Missing graph. I attach it in the answer.

In a uniformly accelerated motion, the velocity at time t is given by:
$v(t)=at$
where a is the acceleration and t is the time.

Given the previous equation, if we plot v(t) versus t, we find a straight line; moreover, a (the acceleration) represents the slope of the curve.

Looking at the graph, we see that when the time goes from 10 s to 20 s, the velocity increases from 4 m/s to 6 m/s. Therefore the slope of the curve is
$a= \frac{\Delta v}{\Delta t}= \frac{6 m/s-4 m/s}{20 s-10 s}= \frac{2 m/s}{10 s}=0.2 m/s^2$
and this corresponds to the acceleration.

So, the correct answer is 0.2 m/s2.

7 0

3 years ago

Read 2 more answers

A certain corner of a room is selected as the origin of a rectangular coordinate system. If a fly is crawling on an adjacent wal

asambeis [7]

Answer:

The distance is 3.1 m

Explanation:

The position vector of the fly relative to the corner of the wall is

r = (3.1, 0.5).

The distance of the fly from the corner will be calculated as the magnitude of the vector "r"

magnitude of vector $r = \sqrt{(3.1 m)^{2} + (0.5 m)^{2}} = 3.1 m$

Since the numbers to be added have only one decimal place 3.1 and 0.5, the result of the sum will have to have one decimal place. The result of the square root will also have one decimal place.

5 0

2 years ago

• The average length is ________ cm. This is the mean or average. b)• Subtract the highest value from the lowest value: ________

coldgirl [10]

16, 5 , 3 = 16+5+3= 24 + 3

So at the end put 24 + 3 cm
And put 16 for the lengths
For the value 5 and for the diving thingy 3

7 0

3 years ago

A 12.70 g bullet has a muzzle velocity (at the moment it leaves the end of a firearm) of 430 m/s when rifle with a weight of 25.

Norma-Jean [14]

Answer:

2.1844 m/s

Explanation:

The principle of conservation of momentum can be applied here.

when two objects interact, the total momentum remains the same provided no external forces are acting.

Consider the whole system , gun and bullet. as an isolated system, so the net momentum is constant. In particular before firing the gun, the net momentum is zero. The conservation of momentum,

$0=m_{bullet}*v_{bullet} + m_{rifle}*v_{rifle} \\$

assume the bullet goes to right side and the gravitational acceleration =10 $ms^{-2}$

so now the weight of the rifle= $\frac{25}{10}$

$0=m_{bullet}*v_{bullet} + m_{rifle}*v_{rifle} \\\\0=(12.70*10^{-3}) *430ms^{-1} +(\frac{25}{10} )*v_{rifle} \\v_{rifle} =-2.1844ms^{-1}$

this is a negative velocity to the right side. that means the rifle recoils to the left side

3 0

3 years ago

Which of the following are true? Select all that apply. The net electric field at any location inside a block of copper is zero

Agata [3.3K]

Answer:

1) The net electric field at any location inside a block of copper is zero if the copper block is in equilibrium.

2) In equilibrium, there is no net flow of mobile charged particles inside a conductor.

3) If the net electric field at a particular location inside a piece of metal is not zero, the metal is not in equilibrium.

Explanation:

1) and 3) A block of copper is a conductor. The charged particles on a conductor in equilibrium are at rest, so the intensity of the electric field at all interior points of the conductor is zero, otherwise, the charges would move resulting in an electric current.

2) The charged particles on a conductor in equilibrium are at rest.

6 0

3 years ago