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3 years ago

13. You push with 56 N on a 15-kg box, and there is a 23-N force of friction. How fast will the box accelerate?

Physics

1 answer:

Flura [38]3 years ago

4 0

Answer:

The acceleration is 2.2 m/s^2

Explanation:

In the attached image, we can see the free body diagram. And using the second law of Newton it will be possible to find the acceleration of the box.

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If the jet is moving at a speed of 1140 km/h at the lowest point of the loop, determine the minimum radius of the circle so that

AnnZ [28]

To solve this problem we will apply the concepts related to the centripetal Force and the Force given by weight and formulated in Newton's second law. Through the two expressions we can find the radius of curve made in the hand. To calculate the normal force, we will include the concepts of sum of forces to obtain the net force on the body at the top and bottom of the maneuver. The expression for centripetal force acting on the jet is

$F_c = \frac{mv^2}{r}$

According to Newton's second law, the net force acting on the jet is

F = ma

Here,

m = mass

a = acceleration

v = Velocity

r = Radius

PART A ) Equating the above two expression the equation for radius is

$\frac{mv^2}{r} = ma$

$r = \frac{v^2}{a}$

Replacing with our values we have that

$r = \frac{(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{7(9.8m/s^2)}$

$r = 1.462*10^3m$

PART B )

<u>- The expression for effective weight of the pilot at the bottom of the circle is</u>

$N = mg +\frac{mv^2}{r}$

$N = (69kg)(9.8m/s^2)+\frac{(69)(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{1.462*10^3m}$

$N = 5408.87N$

<em>Note that the normal reaction N is directed upwards and gravitational force mg is directed downwards. At the bottom of the circle, the centripetal force is directed upwards. So the centripetal force is obtained from the gravitational force and the normal reaction. </em>

<u>- The expression for effective weight of the pilot at the top of the circle is</u>

$N = mg -\frac{mv^2}{r}$

$N = (69kg)(9.8m/s^2)-\frac{(69)(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{1.462*10^3m}$

$N = 4056.47N$

<em>Note that at the top of the circle the centripetal force is directed downwards. So the centripetal force is obtained from normal reaction and the gravitational force. </em>

4 0

3 years ago

A snowball is thrown with an initial x velocity of 7.5 m/s and an initial y velocity of 8.4 m/s . Part A How much time is requir

elena55 [62]

In order to calculate the time taken by the snowball to reach the highest point in its journey, we need to consider the variables along the y-direction.

Let us list out what we know from the question so that we can decide on the equation to be used.

We know that Initial Y Velocity $V_{iy}$ = 8.4 m/s

Acceleration in the Y direction $a_{y}$ = -9.8 m/ $s^{2}$ , since the acceleration due to gravity points in the downward direction.

Final Y Velocity $V_{fy}$ = 0 because at the highest point in its path, an object comes to rest momentarily before falling down.

Time taken t = ?

From the list above, it is easy to see that the equation that best suits our purpose here is $V_{fy} = V_{iy} + a_{y}t$

Plugging in the numbers, we get 0 = 8.4 - (9.8)t

Solving for t, we get t = 0.857 s

Therefore, the snowball takes 0.86 seconds to reach its highest point.

8 0

4 years ago

A voltage is applied to a resistor,

ladessa [460]

Answer:

Explanation:

By Ohms Law, Voltage = Current * Resistance

Keeping the voltage the same and doubling the resistance, the current will be halved.

So the new current = 1.5/2 = 0.75A

6 0

3 years ago

GP A sinusoidal wave traveling in the negative x direction (to the left) has an amplitude of 20.0 cm, a wavelength of 35.0 cm, a

SIZIF [17.4K]

The period of the wave is determined as 0.083 seconds.

<h3>What is period of a wave?</h3>

The period of a wave is the time taken by a particle of the medium to complete one vibration.

<h3>Period of the wave</h3>

The period of the wave is calculated as follows;

T = 1/f

where;

T is the period of the wave
f is frequency of the wave

T = 1/12

T = 0.083 seconds

Thus, the period of the wave is determined as 0.083 seconds.

Learn more about period of a wave here: brainly.com/question/18818486

#SPJ4

8 0

1 year ago

A particle of mass 4.5 × 10-8 kg and charge +5.4 μC is traveling due east. It enters perpendicularly a magnetic field whose magn

egoroff_w [7]

Answer:

0.00970 s

Explanation:

The centripetal force that causes the charge to move in a circular motion = The force exerted on the charge due to magnetic field

Force due to magnetic field = qvB sin θ

q = charge on the particle = 5.4 μC

v = velocity of the charge

B = magnetic field strength = 2.7 T

θ = angle between the velocity of the charge and the magnetic field = 90°, sin 90° = 1

F = qvB

Centripetal force responsible for circular motion = mv²/r = mvw

where w = angular velocity.

The centripetal force that causes the charge to move in a circular motion = The force exerted on the charge due to magnetic field

mvw = qvB

mw = qB

w = (qB/m) = (5.4 × 10⁻⁶ × 2.7)/(4.5 × 10⁻⁸)

w = 3.24 × 10² rad/s

w = 324 rad/s

w = (angular displacement)/time

Time = (angular displacement)/w

Angular displacement = π rads (half of a circle; 2π/2)

Time = (π/324) = 0.00970 s

Hope this Helps!!!

4 0

3 years ago