The minimum number of vectors of unequal magnitude required to

maxonik [38]

D. Was a leader in the woman's suffrage movement

7 0

3 years ago

Ezra (m = 20.0 kg) has a tire swing and wants to swing as high as possible. He thinks that his best option is to run as fast as

Dmitriy789 [7]

Answer:

a) $v=5.6725\,m.s^{-1}$

b) $h= 1.6420\,m$

Explanation:

Given:

mass of the body, $M=20\,kg$

mass of the tyre, $m=10\,kg$

length of hanging of tyre, $l=3.5m$

distance run by the body, $d=10m$

acceleration of the body, $a=3.62m.s^{-2}$

(a)

Using the equation of motion :

$v^2=u^2+2a.d$ ..............................(1)

where:

v=final velocity of the body

u=initial velocity of the body

here, since the body starts from rest state:

$u=0m.s^{-1}$

putting the values in eq. (1)

$v^2=0^2+2\times 3.62 \times 10$

$v=8.5088\,m.s^{-1}$

Now, the momentum of the body just before the jump onto the tyre will be:

$p=M.v$

$p=20\times 8.5088$

$p=170.1764\,kg.m.s^{-1}$

Now using the conservation on momentum, the momentum just before climbing on the tyre will be equal to the momentum just after climbing on it.

$(M+m)\times v'=p$

$(20+10)\times v'=170.1764$

$v'=5.6725\,m.s^{-1}$

(b)

Now, from the case of a swinging pendulum we know that the kinetic energy which is maximum at the vertical position of the pendulum gets completely converted into the potential energy at the maximum height.

So,

$\frac{1}{2} (M+m).v'^2=(M+m).g.h$

$\frac{1}{2} (20+10)\times 5.6725^2=(20+10)\times 9.8\times h$

$h\approx 1.6420\,m$

above the normal hanging position.

3 0

3 years ago

If he completes the 200 m dash in 23 s and runs at constant speed throughout the race, what is his centripetal acceleration as h

Blababa [14]

Incomplete question.The complete one is here

A runner taking part in the 200m dash must run around the end of a track that has a circular arc with a radius curvature of 30m. The runner starts the race at a constant speed. If she completes the 200m dash in 23s and runs at constant speed throughout the race, what is her centripetal acceleration as she runs the curved portion of the track?

Answer:

$a_c=2.523m/s^2$

Explanation:

Given data

$L_{length}=200m\\r_{radius}=30m\\t_{time}=23s$

Required

Centripetal acceleration

Solution

According to the motions equation the velocity given by:

$V_{velocity}=\frac{L_{length}}{t_{time}}\\V_{velocity}=\frac{200m}{23s}\\V_{velocity}=8.7m/s$

The centripetal acceleration is given by:

$a_{c}=\frac{V_{velocity}^2}{r_{radius}}\\ a_c=\frac{(8.7m/s)^2}{30m}\\ a_c=2.523m/s^2$

4 0

3 years ago

Technician A says balance shafts are used to counteract vibration created in the engine. Technician B says proper balancing of t

kompoz [17]

Answer:

both technician A and Technician B are correct

Explanation:

Technician A says balance shafts are used to counteract vibration created in the engine. Technician B says proper balancing of the engine is important for smooth operation. Which technician is correct

In piston engine engineering, a balance shaft is an eccentric weighted shaft that counteracts vibrations in engine designs that are not inherently balanced. They were first invented and patented by British engineer Frederick W. Lanchester in 1904. ... .The balance shafts have eccentric weights and rotate in opposite direction to each other, which generates a net vertical force. Unavailability of the balance shaft can cause excessive vibration to the engine thereby damaging the oil pump and resulting to engine failure.

7 0

3 years ago

_____ Is a process that invloves the collection of information and ideas supported by evidence

zalisa [80]

Answer:

Science - is a process that involves the collection of information and ideas supportedby evidence.

6 0

3 years ago

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