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2 years ago

What constant acceleration is required to increase the speed of a car from 20 mi/h to 51 mi/h in 3 seconds

Physics

1 answer:

sdas [7]2 years ago

8 0

Answer:

Explanation:

acceleration is the time rate of change of velocity

a = (51 - 20) / 3 = 10⅓ mi/hr/s

which should probably be converted to standard units.

10⅓ mi/hr/s(5280 ft/mi) / 3600 s/hr) = 15.15555... ≈ 15.2 ft/s²

which is roughly half the acceleration of gravity.

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A satellite is always being pulled by gravity. a. True b. False

tangare [24]

This is true. Gravity is constantly pulling on anything and everything (even light!), no matter how far away it is from another object.

3 0

3 years ago

There is a clever kitchen gadget for drying lettuce leaves after you wash them. It consists of a cylindrical container mounted s

lukranit [14]

Answer:

Option B

$a=19 m/s^{2}$

Explanation:

Given information

Radius of container, r=12cm=12/100=0.12m

Angular velocity= 2 rev/s, converted to rad/s we multiply by 2π

Angular velocity, $\omega=2*2\pi =12.56637061$

We know that speed, $v=r\omega$

Centripetal acceleration, $a=\frac {v^{2}}{r}$ and substituting $v=r\omega$ we obtain that

$a=r\omega^{2}$

Substituting \omega for 12.56637061 and r for 0.12

$a=0.12*(12.56637061)^{2}=18.94964045 m/s^{2}$

Rounded off, $a=19 m/s^{2}$

7 0

3 years ago

A student hangs a weight on a newtonmeter. The energy currently stored in the spring in the newton meter is 0.045N. The student

castortr0y [4]

Answer:

5x10^-3

Explanation:

Hooke's Law states that the force needed to compress or extend a spring is directly proportional to the distance you stretch it.

Hooke's Law can be represented as

where F is the force

k is the spring constant

x is the extension of the material

Plug values in the equation

Step 1 find the original extension

0.045 = (400)x

x = 1.125x 10^-4 m d

Step 2 find the new extension

0.045+2 = 400(x)

2.045 = 400x

x = 5.1125x10^-3

Step 3 subtract the new extension with original

Total extension of the spring = 5.1125x10^-3 - 1.125x 10^-4 m = 5x10^-3

8 0

3 years ago

1. How does the structure of a hard-boiled egg compare to the crust, mantle, and core structure of Earth? What do the egg's laye

lutik1710 [3]

Answer:

2. Earth layers compare in egg layer it is hard on the outside

Explanation:

6 0

3 years ago

Read 2 more answers

PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!!

Sonbull [250]

Question 1

In order to do work, the force vector must be

in the same direction as the displacement vector and the motion.

Question 2

In which of the following cases is work being done on an object?

Pulling a trailer up a hill

Question 3

Which situation is an example of NOT doing work?

carrying a box

Question 4

Work is measured in

Joules

Question 5

To find the work done, the force exerted and distance moved are multiplied. A couch is moved twice before you are happy with its placement. The same force was used to move the couch both times. If more work is done the first time it is moved, what do you know about the distance it was moved?

When more work was done, the couch was moved further.

Question 6

A weight lifter raises a 1600 N barbell to a height of 2.0 meters. How much work was done? W = Fd

3200 Joules

Question 7

You and a friend (Alex) are at a a tree-top adventure park .. . . part of the course requires you to climb up a rope. You both climb the same rope in the same amount of time. However, the tension in the rope is greater

when Alex climbs. Who did the most work?

Alex did - more tension means more force - more force means more work was done

Question 8

Doing work at a faster rate creates power.

more

Question 9

In one challenge on the Titan Games, competitors have to lift 200 pounds up a long ramp. Angel is able to move the weight in 42 seconds. Anthony gets it done in only 38 seconds. Which statement is true?

Anthony has more power than Angel.

Question 10

A mountain climber exerts 41,000 J of work to climb a cliff. How much power does the climber need if she wants to finish in only 500 seconds? Power = Work / time

82 Watts

Question 11

Your family is moving to a new apartment. While lifting a box 83 Joules of work is done to put the box on a truck, you exert an upward force of 75 N for 3 s. How much power is required to do this? (Hint: You only need two of the 3 numbers given!) Power = Work / time

27.7 Watts

*100% CORRECT ANSWERS

4 0

3 years ago