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fenix001 [56]
3 years ago
15

A block with mass m1 = 4.50 kg and a ball with mass m2 = 7.70 kg are connected by a light string that passes over a frictionless

pulley, as shown in figure (a). The coefficient of kinetic friction between the block and the surface is 0.300. 
(a) Find the acceleration of the two objects and the tension in the string. 
(b) Check the answer for the acceleration by using the system approach. (Use the following as necessary: m1, m2, μk, and g.) 
(c) What if an additional mass is attached to the ball? How large must this mass be to increase the downward acceleration by 60%? 

For (a) I calculated acceleration to be 5.10 m/s^2 and tension to be 36.2N. 
For (b) I the equation is a = (m2g-ukm1g)/(m1+m2) 
It is (c) that I cannot figure out. Can anybody please help me?
Physics
1 answer:
Allisa [31]3 years ago
4 0
1.6a =  \frac{g(m_2 + m_3 - \mu km_1)}{m_1 + m_2 + m_3}  \\  \\ 1.6a(m_1 + m_2 + m_3) = g(m_2 + m_3 - \mu km_1) \\  \\ (1.6a + \mu kg)m_1 + (1.6a - g)m_2 = (g - 1.6a)m_3 \\  \\ m_3 =  \frac{1.6a +\mu kg}{g - 1.6a} m_1 - m_2 \\  \\ m_3 = 22.57 kg
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Explanation:

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A turntable must spin at 33.4 rpm (3.50 rad/s) to play an old-fashioned vinyl record. how much torque must the motor deliver if
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In order to compute the torque required, we may apply Newton's second law for circular motion:
Torque = moment of inertia * angular acceleration

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α = Δω/Δt
The time taken to achieve rotational speed may be calculated using:
time = 1 revolution * 2π radians per revolution / 3.5 radians per second
time = 1.80 seconds

α = (3.5 - 0) / 1.8
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How often is water added to the Earth system?
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4 years ago
14. a ball is thrown horizontally from the roof of a building 75 m tall with a speed of 4.6 m/s. a. how much later does the ball
Burka [1]

The time taken to hit the ground is 3.9 s, the range is 18m and the final velocity is 42.82 m/s

<h3>Motion Under Gravity</h3>

The motion of an object under gravity is the vertical motion of the object under the influence of acceleration due to gravity.

Given that a ball is thrown horizontally from the roof of a building 75 m tall with a speed of 4.6 m/s.

a. how much later does the ball hit the ground?

The time can be calculated by considering the vertical component of the motion with the use of formula below.

h = ut + 1/2gt²

Where

  • Height h = 75 m
  • Initial velocity u = 0 ( vertical velocity )
  • Acceleration due to gravity g = 9.8 m/s²
  • Time t = ?

Substitute all the parameters into the formula

75 = 0 + 1/2 × 9.8 × t²

75 = 4.9t²

t² = 75/4.9

t² = 15.30

t = √15.3

t = 3.9 s

b. how far from the building will it land?

The range can be found by using the formula

R = ut

Where u = 4.6 m/s ( horizontal velocity )

R = 4.6 × 3.9

R = 18 m

c. what is the velocity of the ball just before it hits the ground?

The final velocity will be

v = u + gt

v = 4.6 + 9.8 × 3.9

v = 4.6 + 38.22

v = 42.82 m/s

Therefore, the answers are 3.9 s, 18 m and 42.82 m/s

Learn more about Vertical motion here: brainly.com/question/24230984

#SPJ1

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Explanation:

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