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DanielleElmas [232]
3 years ago
10

A hooligan throws a stone vertically down with an initial speed of 17 m/s from the roof of a building 51 metres above the

Physics
1 answer:
pshichka [43]3 years ago
4 0

Answer:

Explanation:

impact velocity is

√(18² + 2(-9.8)-51) = 36 m/s

average velocity is (17 + 36)/2 = 26.5 m/s

t = d/v = 51 / 26.5 = 1.9 s

or

if ground is origin and UP positive

0 = 51 - 17t - ½(9.8)t²

quadratic formula

t = (17 ±√(17² - 4(-4.9)(51))) / (2(-4.9))

t = (17 ± 36) / -9.8

t = - 5.4 s which we ignore as the stone is not thrown yet

or

t = 19 s

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A small sphere with mass m is attached to a massless rod of length L that is pivoted at the top, forming a simple pendulum. The
USPshnik [31]

Answer:

a) see attached, a = g sin θ

b)

c)   v = √(2gL (1-cos θ))

Explanation:

In the attached we can see the forces on the sphere, which are the attention of the bar that is perpendicular to the movement and the weight of the sphere that is vertical at all times. To solve this problem, a reference system is created with one axis parallel to the bar and the other perpendicular to the rod, the weight of decomposing in this reference system and the linear acceleration is given by

          Wₓ = m a

          W sin θ = m a

          a = g sin θ

b) The diagram is the same, the only thing that changes is the angle that is less

                θ' = 9/2  θ

             

c) At this point the weight and the force of the bar are in the same line of action, so that at linear acceleration it is zero, even when the pendulum has velocity v, so it follows its path.

The easiest way to find linear speed is to use conservation of energy

Highest point

            Em₀ = mg h = mg L (1-cos tea)

Lowest point

          Emf = K = ½ m v²

          Em₀ = Emf

          g L (1-cos θ) = v² / 2

              v = √(2gL (1-cos θ))

4 0
3 years ago
Which two of the following actions would
Ganezh [65]
Answer is d using a heavier string
5 0
3 years ago
Which one of these wireless technologies are not in the permeable zone of the radio wave spectrum
k0ka [10]

Answer:

Explanation:

3 and 4G networks, Bluetooth, and Wi-Fi technologies. my opinions

4 0
3 years ago
A 3.30-kg block starts from rest at the top of a 30.0° incline and slides a distance of 2.10 m down the incline in 1.60 s.(a) fi
AnnZ [28]
<span>Mass of the block m = 3.3kg Angle of the slide = 30 degrees Distance the block slides s = 2.10 m Time taken to slide t = 1.6 s Initially in rest condition so initial velocity u = 0. We have an equation for distance s = (u x t) + (1/2) x (a t^2) s = (0 x t) + (1/2) x (a x (1.6) ^2) => 2.10 = (1/2) x (a x2.56) 2.56a = 4.20 => a = 1.64 So the magnitude of the Acceleration a = 1.64 m/s^2</span>
8 0
3 years ago
A car of mass 2200 kg collides with a truck of mass 4500 kg, and just after the collision the car and truck slide along, stuck t
katovenus [111]

Answer:

37.7m/s: principle of conservation of momentum

Explanation:

The principle to make use of is the principle of conservation of momentum which States that the sum of momentum of bodies before collision is equal to the sum of momentum of bodies after collision. This bodies will move with the same velocity after collision.

Momentum = Mass × velocity

For car of mass 2200kg moving with velocity 33m/s:

Momentum of car before collision = 2200×33

= 72,600kgm/s

For the truck of mass 4500kg;

Momentum = 4500 ×(22-(-18)

= 4500×40

= 180000kgm/s

After collision, their momentum is:

Momentum after collision = (2200+4500)v

= 6700v

Using the principle above to get the common velocity v we have

72600+180000 = 6700v

252600 = 6700v

v = 252600/6700

v = 37.7m/s

7 0
3 years ago
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