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4 years ago

What’s the unit for velocity?

Physics

1 answer:

torisob [31]4 years ago

4 0

Answer:

meter per second

Explanation:

It could be any other unit such as yard or feet, put it will be whatever measure per second or whatever time.

Examples

feet per second

miles per hour

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A ball dropped by melissa is falling downward toward the floor

Artist 52 [7]

What is the question

3 0

3 years ago

Why do we use a spaceship in outer space, far from other objects, to illustrate the principle that an object that does not inter

HACTEHA [7]

Complete Question: Why do we use a spaceship in outer space, far from other objects, to illustrate the principle that an object that does not interact with anything travels at constant speed in a straight line (Newton's first law)? Why not a car or a train? (Select all that apply.)

(1) A car or train touches other objects, and interacts with them.

(2) A car or train can't travel fast enough.

(3) The spaceship has negligible interactions with other objects.

(4) A car or train interacts gravitationally with the Earth.

(5) A spaceship can never experience a gravitational force.

Answer:

(1), (3), (4), (5)

Explanation:

In order to be able to move in a straight line at constant speed forever, as stated by Newton's first law, the object can't be subject to any external net force that can change its momentum.

1) A car, or train, interacts with other objects (the air, the road surface, or the rails, for instance) which means that sooner or later, it will come to an stop, so, for this reason, is not a good fit for that purpose.

3) As it is assumed that the spaceship has negligible interactions with another objects, it will continue moving in a straight line at a constant speed, forever, so it's a good fit to explain Newton's first law.

4) As the train, or a car, or any earthling object, is subject to the gravitational attractive force from Earth, it is not possible for them to move along a straight line at a constant speed forever, as stated by Newton's first law, so a train or a car definitely aren't a good fit in order to explain it.

5) Even though a spaceship can actually experiment a gravitational force from any mass close enough to it, as stated by Newton's Universal Law of Gravitation, in order to simplify things, in this case, usually we neglect any of them.

3 0

3 years ago

You wish to buy a motor that will be used to lift a 10-kg bundle of shingles from the ground to the roof of a house. The shingle

gogolik [260]

Answer:

$\tau=19.21\ N-m$

Explanation:

It is given that,

Mass of bundle of shingles, m = 10 kg

Upward acceleration of the shingles, $a=1.5\ m/s^2$

The radius of the motor of the pulley, r = 0.17 m

Let T is the tension acting on the shingles when it is lifted up. It can be calculated as :

$T-mg=ma$

$T=m(g+a)$

$T=10\times (9.8+1.5)$

T = 113 N

Let $\tau$ is the minimum torque that the motor must be able to provide. It is given by :

$\tau=r\times T$

$\tau=0.17\times 113$

$\tau=19.21\ N-m$

So, the minimum value of torque is 19.21 N-m. Hence, this is the required solution.

4 0

3 years ago

Ocean waves travel in to the beach at an average velocity of 2.5 m/s

ANTONII [103]

1) D) 10.0 m

To find the average distance between the wave peaks, we can use the formula:

$v=\frac{d}{t}$

where in this case:

v = 2.5 m/s is the average velocity

d = ? is the average distance

t = 4 s is the time between two wave peaks

Re-arranging the equation, we find

$d=vt=(2.5 m/s)(4 s)=10.0 m$

2) B) Power

This is exactly the definition of power. In fact, power is defined as the ratio between the amount of work done / of energy used, and the time taken for this conversion to occur:

$P=\frac{W}{t}$

where

W is the amount of work done / of energy used

t is the time taken

3) C) The body builder uses the same energy and but more power.

The energy used by the body builder does not change: in fact, it is only related to the height at which he lift the weight. The work done to lift the weight, of mass m, up to a height of h, is given by

$W=mgh$

where g is the gravitational acceleration. So, this quantity does not change. Instead, the power changes, because the time the body builder takes to lift the weight up has decreased, and the power depends on the time as we know from the formula:

$P=\frac{W}{t}$

so, since t has decreased, P has increased.

4) D) body mass, final height, and the time required to complete the climb

The power output is given by:

$P=\frac{W}{t}=\frac{mgh}{t}$