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3 years ago

A car traveling at a speed of 30 m/s encounters an emergency and comes to a complete

Physics

1 answer:

Natasha2012 [34]3 years ago

4 0

Answer:

Explanation:

Use the one-dimensional equation

$v_f=v_0+at$ which says that the final velocity of an object is equal to the object's initial velocity plus its acceleration times time. We are looking for time. That means the equation looks like this:

0 = 30 + (-4)t and

-30 = -4t so

t = 7.5 sec

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Calculate the magnitude of the total impulse applied to the car to bring it to rest

n200080 [17]

Answer:

Total impulse = $mv$ = Initial momentum of the car

Explanation:

Let the mass of the car be 'm' kg moving with a velocity 'v' m/s.

The final velocity of the car is 0 m/s as it is brought to rest.

Impulse is equal to the product of constant force applied to an object for a very small interval. Impulse is also calculated as the total change in the linear momentum of an object during the given time interval.

The magnitude of impulse is the absolute value of the change in momentum.

$|J|=|p_f-p_i|$

Momentum of an object is equal to the product of its mass and velocity.

So, the initial momentum of the car is given as:

$p_i=mv$

The final momentum of the car is given as:

$p_f=m(0)=0$

Therefore, the impulse is given as:

$|J|=|p_f-p_i|=|0-mv|=|-mv|=mv$

Hence, the magnitude of the impulse applied to the car to bring it to rest is equal to the initial momentum of the car.

5 0

3 years ago

What is the kinetic energy of an object that has a mass of 50.0 kg and a velocity of 18 m/s? A.450 J B.900 J C.8,100 J D.16,000

Svet_ta [14]

KE = (1/2)·(mass)·(speed)²

KE = (1/2)·(50 kg)·(18 m/s)²

KE = (25 kg)·(324 m²/s²)

KE = 8,100 kg-m²/s²

KE = 8,100 Joules

5 0

3 years ago

Read 2 more answers

(30 points!)Which of the following musical instruments has the greatest inertia

faltersainse [42]

The answer is B.) hope this helps

3 0

3 years ago

Read 2 more answers

A luge run is straight for the first 10 m. If the velocity of the luger when he passes the start line is +25 m/s and his acceler

dangina [55]

V^2 =U^2 +2AS
V^2 = 25 ^2 + 2x9.5x10
V^2 = 625 + 1900 = 2525
V = 50.25

3 0

3 years ago

Which statement is correct?

NISA [10]

Answer:

1st statement is true

Explanation:

Here statement 1 is correct

Let think about it, if you push down the bar then you are lifting your weight off the pedals.

Obviously, this question does not take into account of racing bikes with straps on pedals, where you would push on one side and pull on the other to match your legs are doing, with straps your other leg can pull pedals upward.

5 0

3 years ago