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2 years ago

You are going 30 m/s in a car of mass 1000 kg when you reach a red light and stop your car.

Physics

1 answer:

Radda [10]2 years ago

5 0

Answer:

Explanation:

The kinetic energy will convert to heat energy (provided the car has friction brakes and not regenerative brakes as might be found on an electric or hybrid) Also<u> assuming level road</u>.

E = ½mv² = ½(1000)30² = 450,000 J

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Newton's first law of motion states that an object will keep a constant speed and direction unless acted upon by an unbalanced f

trasher [3.6K]

Answer:

The unbalanced force that caused the ball to stop was friction

Explanation:

As Newton's second law states, the acceleration of an object is proportional to the net force applied on the object:

$F=ma$

therefore, in order to move at constant speed, an object should have a net force of zero (balanced forces) acting on it.

In this case, the ball slows down and eventually comes to a stop: it means that the ball is decelerating, so there are unbalanced forces (net force different from zero) acting on it. The unbalanced force acting on the ball is the friction: friction is a force against the motion of the object, which is due to the contact between the surface of the ball and the surface of the street, and this force is responsible for slowing down the ball.

3 0

2 years ago

Read 2 more answers

How fast can a 4000 kg truck travel around a 70 m radius turn without skidding if its tires share a 0.6 friction coefficient wit

aleksley [76]

Answer:

Velocity of truck will be 20.287 m /sec

Explanation:

We have given mass of the truck m = 4000 kg

Radius of the turn r = 70 m

Coefficient of friction $\mu =0.6$

Centripetal force is given $F=\frac{mv^2}{r}$

And frictional force is equal to $F_{frictional}=\mu mg$

For body to be move these two forces must be equal

So $\frac{mv^2}{r}=\mu mg$

$v=\sqrt{\mu rg}=\sqrt{0.6\times 70\times 9.8}=20.287m/sec$

7 0

2 years ago

A dancer lifts his partner above his head with an acceleration of 2.5 m/s squared the dancer. Exerts a force of 200N what is the

elena-s [515]

F = ma
F = 200N, a = 2.5m/s^2

200N = (2.5)m
m = 80kg

4 0

2 years ago

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consider the photoelectric effect experiment. in one experiment yellow light shines on a piece of potassium metal. a current is

kompoz [17]

Explanation:

If the intensity of the yellow light increased, meaning more photons will strike the Potassium metal per unit area. This will cause more ejection of electrons from the metal and hence, the strength of current will also increase as we know that

I = Q/t, as the charge increase , the current will also increase.

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2 years ago

Which statement explains the polarity of a water molecule?

timofeeve [1]

Answer:

D. The oxygen side is partially negative because electrons are pulled toward the oxygen side.

Explanation:

The water molecule is polar by the virtue of covalent bonds and the hydrogen bonds within and between its molecule.

The oxygen side is partially negative because the electrons are pulled toward the oxygen side.

Between oxygen and hydrogen that makes up the water molecule, oxygen is more electronegative.

An electronegative atom has more affinity for electrons. Since the electrons in the molecule of water is shared between hydrogen and oxygen, the more electronegative specie which is water draws the electron more to itself.

This leaves a net negative charge on the oxygen atom.

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2 years ago