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2 years ago

Why does the unit of time enter twice in the unit of acceleration?

1 answer:

8 0

Acceleration is the measurement that describes the rate of the changing the speed of the object. Mathematically, that is a = s / t
where a is acceleration, s is speed and t is time. Further, speed is the rate of changing the distance, s = d / t
With this, the unit of time is entered twice in the equation.

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A baggage handler throws a 15 kg suitcase along the floor of an airplane luggage compartment with a speed of 1.2 m/s. The suitca

Hatshy [7]

Answer:

0.0367

Explanation:

The loss in kinetic energy results into work done by friction.

Since kinetic energy is given by

KE=0.5mv^{2}

Work done by friction is given as

W= umgd

Where m is the mass of suitacase, v is velocity of the suitcase, g is acceleration due to gravity, d is perpendicular distance where force is applied and u is coefficient of kinetic friction.

Making u the subject of the formula then we deduce that

$u=\frac {v^{2}}{2gd}$

Substituting v with 1.2 m/s, d with 2m and taking g as 9.81 m/s2 then

$u=\frac {1.2^{2}}{2*9.81*2}=0.0366972477064\approx 0.0367$

Therefore, the coefficient of kinetic friction is approximately 0.0367

7 0

2 years ago

11–8 Consider a heavy car submerged in water in a lake with a flat bottom. The driver’s side door of the car is 1.1 m high and 0

Greeley [361]

Answer:

Explanation:

position of centre of mass of door from surface of water

= 10 + 1.1 / 2

= 10.55 m

Pressure on centre of mass

atmospheric pressure + pressure due to water column

10 ⁵ + hdg

= 10⁵ + 10.55 x 1000 x 9.8

= 2.0339 x 10⁵ Pa

the net force acting on the door (normal to its surface)

= pressure at the centre x area of the door

= .9 x 1.1 x 2.0339 x 10⁵

= 2.01356 x 10⁵ N

pressure centre will be at 10.55 m below the surface.

When the car is filled with air or it is filled with water , in both the cases pressure centre will lie at the centre of the car .

7 0

2 years ago

Four students measured the acceleration of gravity. The accepted value for their location is 9.78m/s2. Which student’s measureme

Lisa [10]

On comparing values , we see that student which has the largest percent error is A. Student 4: 9.61 m/s2 .

Explanation:

Here, we have Four students measured the acceleration of gravity. The accepted value for their location is 9.78m/s2. Let's calculate which student’s measurement has the largest percent error :

A. Student 4: 9.61 m/s2

Percentage of error = $\frac{9.78-9.61}{9.78} (100) = 1.738%$ %.

B. Student 3: 9.88 m/s2

Percentage of error = $\frac{9.88-9.78}{9.78} (100) = 1.022%$ %.

C. Student 2: 9.79 m/s2

Percentage of error = $\frac{9.79-9.78}{9.78} (100) = 0.1022%$ % .

D. Student 1: 9.78 m/s2

Percentage of error = $\frac{9.78-9.61}{9.78} (100) = 0%$ % .

On comparing values , we see that student which has the largest percent error is A. Student 4: 9.61 m/s2 .

4 0

2 years ago

When the wind kicks up dust and sand, the dust grains are charged. The small grains tend to get a negative charge, and the large

diamong [38]

Answer:

Explanation:

Small grains are negatively charged by the wind while big grains is positively charged and remains at the ground . This process creates an electric field due to the presence of oppositely charged particles.

When ever electric field exists it is directed from a positive charge to a negative charge so the here electric field is towards an upwards direction.

4 0

2 years ago

A man has a mass of 66kg on earth. what is his weight?

klasskru [66]

So 1 kg = 2.2 pounds.
66kg | 2.2 pounds
--------| ------------------
| 1kg

I set it up like this. The 66 kg crosses out with the 1kg. So you multiply the top 66 x 2.2 = 145.2 pounds

7 0

2 years ago