A Tesla Roadster car accelerates from rest at a rate of 7.1m/s' for a time of 3.9s.

Pilots can be tested for the stresses of flying high-speed jets in a whirling "human centrifuge," which takes 1.5 min to turn th

nirvana33 [79]

Answer:

(a) Angular acceleration will be $\alpha =18.66rev/min^2$

(B) Final angular velocity will be 28 rev/min

Explanation:

We have given time t = 1.5 min

Angular displacement $\Theta =21rev$

(a) Initial angular speed $\omega _i=0rad/sec$

From second equation of motion we know that $\Theta =\omega _it+\frac{1}{2}\alpha t^2$

So $21 =0\times 1.5+\frac{1}{2}\times \alpha\times 1.5^2$

$42 =\alpha\times 1.5^2$

$\alpha =18.66rev/min^2$

(b) Now from first equation of motion

$\omega _f=\omega _i+\alpha t=0+18.66\times 1.5=28rev/min$

5 0

3 years ago

Read 2 more answers

Turning the barrel of a 50-mm-focal-length lens on a manual-focus camera moves the lens closer to or farther from the sensor to

Yuliya22 [10]

Answer:

Explanation:

To focus object at .7m , the image distance can be measured as follows

object distance u = .7m

focal length f = .05 m

image distance v = ?

from lens formula

$\frac{1}{v} -\frac{1}{u} = \frac{1}{f}$

$\frac{1}{v} +\frac{1}{.7} = \frac{1}{.05}$

$\frac{1}{v} =\frac{1}{.05} -\frac{1}{.7}$

v = .054 m

= 54 mm

when the object is at infinity , image is formed at focus ie at distance of

50 mm .

So lens position from sensor where image is formed , varies from 54 mm to 50 mm .

4 0

3 years ago

15. A machine must move an object 15.1 meters by exerting a 121 Newton force. If the machine

Tcecarenko [31]

The power provided by the machine is 13.24 W.

Answer:

Explanation:

Power is determined as the ratio of work done by the system or on the system to the time interval. As the work done is equal to the product of force acting on the system or by the system with the displacement experienced by the system. The power provided by the machine will be

Power = Work done /Time

As the force is given as 121 N and the displacement is given as 15.1 m in a time interval of 2.3 minutes. The time interval should be changed to seconds for each solving ability.

Time taken = 2.3 * 60 s = 138 s

Power = (121×15.1)/138 = 13.24 W.

So the power provided by the machine is 13.24 W.

6 0

3 years ago

A 1200-kg SUV is moving alone a straight highway at 12.0 m/s. Another car, with mass 1800 kg and speed 20.0 m/s, has its center

andreev551 [17]

Answer:

A) d = 24 m

B) 50400 kg.m/s

C) v₀ = 16.8 m/s

D) 50400 kg.m/s. It's equal to the momentum found in part B.

Explanation:

We are given;

Mass of station wagon;m1 = 1200 kg Velocity; V = 12 m/s

Mass of car; m2 = 1800 kg

Velocity of car; v2 = 20 m/s

a ) Let centre of mass of car and station wagon be at a distance d from wagon

Thus,

If we take moment of weight about it, we have;

1200 x d = 1800 x ( 40 - d )

Where, d is the position of the center of mass of the system consisting of the two cars

Thus,

1200d = 72000 - 1800d

1200d + 1800d = 72000

3000 d = 72,000

d = 72,000/3000

d = 24 m

b ) Total momentum= m1•v1 + m2•v2

= (1200 x 12) + (1800 x 20)

= 14400 + 36000

= 50400 kg.m/s

c ) Let speed of centre of mass be v₀

Thus,

v₀ = (m1•v1 + m2•v2)/(m1 + m2)

v₀ = 50400/(1200 + 1800)

v₀ = 50400/3000

v₀ = 16.8 m/s

d) System Total momentum = velocity of centre mass x total mass

Thus,

Total momentum = v₀(m1 + m2)

= 16.8(3000) = 50400 kg.m/s .

This value is equal to what was calculated in part b

8 0

3 years ago

What is the net work done on the 20kg block while it moves the 4 meters?

Vinil7 [7]

Answer:

The answer to your question is 784.8 J. None of your answer, did you forget some information?

Explanation:

Data

mass = 20 kg

distance = 4 m

work = ?

Formula

Work = force x distance

Force = mass x gravity

Process

1.- Calculate the weight of the block

Weight = 20 x 9.81

Weight = 196.2 N

2.- Calculate the work done

Work = 196.2 x 4

Work = 784.8 J

5 0

3 years ago