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3 years ago

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A soccer player is running upfeild at 10m/s and comes to a stop in 3 seconds facing in the same direction what is his accelerati

on

1 answer:

kumpel [21]3 years ago

6 0

-3.33 m/s^2

The soccer player decelerates from 10 m/s to 0 m/s. Because he decelerates the acceleration will be a negative value. Since he takes 3 seconds to decelerate, divide his original velocity by 3

One major point to be careful of is to keep p

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What happens to a circuit's resistance (R), voltage (V), and current (1) when

hammer [34]

Answer:

D.

R increases

V is constant

I decreases

Explanation:

The resistance of a wire is given by the following formula:

$R = \frac{(Resistivity)(L)}{A}$

It is clear from this formula that resistance is directly proportional to the length of wire. So, when length of wire is increased, <u>the resistance of circuit increases</u>.

The <u>voltage in the circuit will be constant</u> as the voltage source remains same and it is not changed.

Now, we can use Ohm Law:

V = IR

at constant V:

I ∝ 1/R

it means that current is inversely proportional to resistance. Hence, the increase of resistance causes <u>the current in circuit to decrease.</u>

Therefore, the correct option will be:

<u>D.</u>

<u>R increases </u>

<u>V is constant </u>

<u>I decreases</u>

6 0

2 years ago

A bowling ball has a mass of 5 kg. A student rolls the bowling ball one time at 1 m/s and a second time and 2 m/s. Compare the m

sasho [114]

The answer is 5kg m/s with the second momentum being 10 kg m/s. i took the test and it was right. hope this helps yalls

5 0

2 years ago

Dafna11 [192]

Answers:

a) -2.54 m/s

b) -2351.25 J

Explanation:

This problem can be solved by the <u>Conservation of Momentum principle</u>, which establishes that the initial momentum $p_{o}$ must be equal to the final momentum $p_{f}$ :

$p_{o}=p_{f}$ (1)

Where:

$p_{o}=m_{1} V_{o} + m_{2} U_{o}$ (2)

$p_{f}=(m_{1} + m_{2}) V_{f}$ (3)

$m_{1}=110 kg$ is the mass of the first football player

$V{o}=-7 m/s$ is the velocity of the first football player (to the south)

$m_{2}=75 kg$ is the mass of the second football player

$U_{o}=4 m/s$ is the velocity of the second football player (to the north)

$V_{f}$ is the final velocity of both football players

With this in mind, let's begin with the answers:

a) Velocity of the players just after the tackle

Substituting (2) and (3) in (1):

$m_{1} V_{o} + m_{2} U_{o}=(m_{1} + m_{2}) V_{f}$ (4)

Isolating $V_{f}$ :

$V_{f}=\frac{m_{1} V_{o} + m_{2} U_{o}}{m_{1} + m_{2}}$ (5)

$V_{f}=\frac{(110 kg)(-7 m/s) + (75 kg) (4 m/s)}{110 kg + 75 kg}$ (6)

$V_{f}=-2.54 m/s$ (7) The negative sign indicates the direction of the final velocity, to the south

b) Decrease in kinetic energy of the 110kg player

The change in Kinetic energy $\Delta K$ is defined as:

$\Delta K=\frac{1}{2} m_{1}V_{f}^{2} - \frac{1}{2} m_{1}V_{o}^{2}$ (8)

Simplifying:

$\Delta K=\frac{1}{2} m_{1}(V_{f}^{2} - V_{o}^{2})$ (9)

$\Delta K=\frac{1}{2} 110 kg((-2.5 m/s)^{2} - (-7 m/s)^{2})$ (10)

Finally:

$\Delta K=-2351.25 J$ (10) Where the minus sign indicates the player's kinetic energy has decreased due to the perfectly inelastic collision

6 0

3 years ago

The brainstem is to breathing and arousal as the limbic system is to memories and: (2 points)

riadik2000 [5.3K]

Answer:

The brainstem is to breathing and arousal as the limbic system is to memories and emotion. See the explanation below, please.

Explanation:

The limbic system develops certain responses to emotional stimuli (joy, anger, sadness, fear, pleasure). It interacts with the autonomic endocrine and nervous system. It is also related to sexuality, memory, attention, memories. It includes some areas such as hypothalamus, tonsil, hippocampus, among others.

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3 years ago

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3 years ago