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BabaBlast [244]

2 years ago

9

during a test crash an airbag inflates to stop a dummies forward motion. the dummies mass is 75 kg. if the net force on the dumm

y is 825N toward the rear of the car what is the dummies deceleration

2 answers:

marta [7]2 years ago

6 0

Answer:

Dummies deceleration is 11m/s²

Explanation:

According to Newton's second law, the relationship between the force applied to an object, its mass, and the acceleration (or deceleration) caused, is given by:

$F=ma$

Solving for acceleration:

$a=\frac{F}{m}$

If we plug in the vales (taking into account the negative sign of the force, as its directed backwards):

$a=\frac{-825N}{75kg}=-11m/s^2$

$a=-11m/s^2$

Deceleration is simply the magnitude of negative acceleration. Therefore, dummies deceleration is 11m/s²

den301095 [7]2 years ago

5 0

Use Force=Mass x Acceleration (newtons second law states force is directly proportional to the acceleration) so you can say that the force is negative and solve for Acceleration.

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If the were not tilted on its axis ,what would be the result

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We wouldnt have seasons

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2 years ago

You find an unmarked blue laser on your way to physics class. When you get to class you realize you can determine the wavelength

Afina-wow [57]

Answer:

λ = 451.7 nm

Explanation:

The expression for the constructive interference of the double diffraction experiment is

d sin θ = m λ

let's use trigonometry

tan θ = y / L

how the experiment occurs at very small angles

tan θ = sin θ / cos θ = sin θ

sin θ = y / L

we substitute

d y / L = m λ

λ = $\frac{d \ y}{m \ L}$

let's calculate

λ = $\frac{0.342 \ 10^{-3} \ 2.80 \ 10^{-3} }{1 \ 2.12 }$

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5 0

2 years ago

The concept of critical density is just like the idea of escape velocity for a projectile launched from the earth. An object lau

ikadub [295]

Answer:

v = √ 2 G M/ $R_{e}$

Explanation:

To find the escape velocity we can use the concept of mechanical energy, where the initial point is the surface of the earth and the end point is at the maximum distance from the projectile to the Earth.

Initial

Em₀ = K + U₀

Final

$Em_{f}$ = $U_{f}$

The kinetic energy is k = ½ m v²

The gravitational potential energy is U = - G m M / r

r is the distance measured from the center of the Earth

How energy is conserved

Em₀ = $Em_{f}$

½ mv² - GmM / $R_{e}$ = -GmM / r

v² = 2 G M (1 / $R_{e}$ – 1 / r)

v = √ 2GM (1 / $R_{e}$ – 1 / r)

The escape velocity is that necessary to take the rocket to an infinite distance (r = ∞), whereby 1 /∞ = 0

v = √ 2GM / $R_{e}$

5 0

2 years ago

A child whose weight is 287 N slides down a 7.20 m playground slide that makes an angle of 31.0Â° with the horizontal. The coeff

natulia [17]

Answer:

a

$H =212.6 \ J$

b

$v = 7.647 \ m/s$

Explanation:

From the question we are told that

The child's weight is $W_c = 287 \ N$

The length of the sliding surface of the playground is $L = 7.20 \ m$

The coefficient of friction is $\mu = 0.120$

The angle is $\theta = 31.0 ^o$

The initial speed is $u = 0.559 \ m/s$

Generally the normal force acting on the child is mathematically represented as

=> $N = mg * cos \theta$

Note $m * g = W_c$

Generally the frictional force between the slide and the child is

$F_f = \mu * mg * cos \theta$

Generally the resultant force acting on the child due to her weight and the frictional force is mathematically represented as

$F =m* g sin(\theta) - F_f$

Here F is the resultant force and it is represented as $F = ma$

=> $ma = m* g sin(31.0) - \mu * mg * cos (31.0)$

=> $a = g sin(31.0)- \mu * g * cos (31.0)$

=> $a = 9.8 * sin(31.0) - 0.120 * 9.8 * cos (31.0)$

=> $a = 4.039 \ m/s^2$

So

$F_f = 0.120 * 287 * cos (31.0)$

=> $F_f = 29.52 \ N$

Generally the heat energy generated by the frictional force which equivalent tot the workdone by the frictional force is mathematically represented as

$H = F_f * L$

=> $H = 29.52 * 7.2$

=> $H =212.6 \ J$

Generally from kinematic equation we have that

$v^2 = u^2 + 2as$

=> $v^2 = 0.559^2 + 2 * 4.039 * 7.2$

=> $v = \sqrt{0.559^2 + 2 * 4.039 * 7.2}$

=> $v = 7.647 \ m/s$

6 0

2 years ago

Explain how to determine the volume of an irregularly shaped object such as a rock

alexira [117]

If you have no way to accurately measure all of the object's bumps and dimples, then the only way to measure its volume is by means of fluid displacement.

-- Put some water into a graduated (marked) container, read the amount of water, drop the object into the container, and read the new volume in the container. The volume of the object is the difference between the two readings.

-- Alternatively, stand an unmarked container in a large pan, and fill it to the brim. Slowly slowly lower the object into the unmarked container, while the pan catches the water that overflows from it. When the object is completely down in the container, carefully remove the container from the pan, and measure the volume of the water in the pan. It's equal to the volume of the object.

6 0

3 years ago