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3 years ago

⚠️⚠️A driver brakes to stop a car in 3.0 s. The car's momentum was 33,000

Physics

1 answer:

nlexa [21]3 years ago

3 0

Answer: 11000 N

Explanation:

Given that,

Time required to stop car = 3.0 s

The car's momentum = 33,000

kg m/s

magnitude of force = ?

Recall that impulse is equal to the change in momentum of the car, hence

Impulse (I) = Momentum

(Since I = force x time, then

Force x time = momentum)

F x 3.0 s = 33,000 kg m/s

F = 33,000kg m/s / 3.0s

F = 11,000 N

Thus, 11000N of force was used to stop the car.

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40. The emotions of this drug vary from euphoria to detachment to panic.

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Answer:

Marijuana

Explanation:

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2 years ago

a ballistic pendulum is used to measure the speed of high-speed projectiles. A 6 g bullet A is fired into a 1 kg wood block B su

Galina-37 [17]

Answer:

(a) v-bullet = 399.04 m/s

(b) I = 2.38 kg m/s

Explanation:

(a) To calculate the initial speed of the bullet, you first take into account that the kinetic energy of both wood block and bullet, just after the bullet impacts the block, is equal to the potential gravitational energy of block and bullet when the cord is at 60° respect to the vertical.

The potential energy is given by:

$U=(M+m)gh$ (1)

U: potential energy

M: mass of the wood block = 1 kg

m: mass of the bullet = 6g = 6.0*10^-3 kg

g: gravitational constant = 9.8m/s^2

h: distance to the ground

The distance to the ground is calculate d by using the information about the length of the cord and the degrees of the cord respect to the vertical:

$h=l-lsin\theta\\\\h=2.2m-2,2m\ sin60\°=0.29m$

The potential energy is:

$U=(1kg+6*10^{-3}kg)(9.8m/s^2)(0.29m)=2.85J$

Next, the potential energy is equal to kinetic energy of the block and the bullet at the beginning of its motion:

$U=\frac{1}{2}(M+m)v^2\\\\v=\sqrt{2\frac{U}{M+m}}=\sqrt{2\frac{2.85J}{1kg+6*10^{-3}kg}}=2.38\frac{m}{s}$

Next, you use the momentum conservation law, in order to calculate the speed of the bullet before the impact:

$Mv_1+mv_2=(M+m)v$ (2)

v1: initial velocity of the wood block = 0m/s

v2: initial speed of the bullet

v: speed of bullet and block = 2.38m/s

You solve the equation (2) for v2:

$M(0)+mv_2=(M+m)v$

$v_2=\frac{M+m}{m}v=\frac{1kg+6*10^{-3}kg}{6*10^{-3}kg}(2.38m/s)\\\\v_2=399.04\frac{m}{s}$

The speed of the bullet before the impact with the wood block is 399.04 m/s

(b) The impulse is gibe by the change in the velocity of the block, multiplied by the mass of the block:

$I=M\Delta v=M(v-v_1)=(1kg)(2.38m/s-0m/s)=2.38kg\frac{m}{s}$

The impulse is 2.38 kgm/s

(c) The force on the cord after the impact is equal to the centripetal force over the block and bullet. That is:

$T=F_c=(M+m)\frac{v^2}{l}=(1.006kg)\frac{(2.38m/s)^2}{2.2m}=2.59N$

The force on the cord after the impact is 2.59N

4 0

3 years ago

A) A mass spectrometer has a velocity selector that allows ions traveling at only one speed to pass with no deflection through s

KengaRu [80]

Answer:

(A). The speed of the ions is $1.2\times10^{6}\ m/s$

(B). The radius of curvature of a singly charged lithium ion is $2.0\times10^{6}\ m$

Explanation:

Given that,

Electric field = 60000 N/C

Magnetic field = 0.0500 T

(A). We need to calculate the velocity

For no deflection

$F_{E}=F_{B}$

$Eq=Bqv$

$v = \dfrac{E}{B}$

$v=\dfrac{60000}{0.0500}$

$v=1.2\times10^{6}\ m/s$

(B). We need to calculate the radius

Using magnetic force balance by centripetal force

$Bqv=\dfrac{mv^2}{r}$

$r=\dfrac{mv^2}{Bqv}$

Put the value into the formula

$r=\dfrac{1.16\times10^{-26}\times(1.2\times10^{6})^2}{0.0500\times1.6\times10^{-19}}$

$r=2.0\times10^{6}\ m$

Hence, (A). The speed of the ions is $1.2\times10^{6}\ m/s$

(B). The radius of curvature of a singly charged lithium ion is $2.0\times10^{6}\ m$

6 0

3 years ago

Two out-of-tune flutes play the same note. One produces a tone that has a frequency of 248 Hz, while the other produces 288 Hz.

zaharov [31]

Answer:

F = 268 Hz

Explanation:

The beat frequency is given as:

$Beat Frequency = |Frequency 1 - Frequency 2|\\$ |

So, for the first flute and tuning fork:

$20 Hz = |248 Hz - F|$

where,

F = Frequency of tuning fork

F = 248 Hz ± 20 Hz

F = 268 Hz (OR) 228 Hz

Now, for the second flute and tuning fork:

$20 Hz = |288 Hz - F|$

where,

F = Frequency of tuning fork

F = 288 Hz ± 20 Hz

F = 268 Hz (OR) 308 Hz

Since, 268 Hz is common from both calculations. Therefore, it will be the frequency of the tuning fork.

3 0

3 years ago

When water droplets in clouds become heavy, they fall to earth as _______ ?

nexus9112 [7]

Answer:D: Precipitation please give brainliest

Explanation: As liquid is heated by the sun's warmth, it changes into a gas form and rises in the atmosphere. In the air, water vapor cools and returns to a liquid form. ... These water droplets cling together and form clouds. When the droplets become heavy enough, they fall to the ground as precipitation.

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3 years ago