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3 years ago

An object with a mass of 78kg is lifted through a height of 6 meters. How much work is done?

1 answer:

3 0

Work = force x distance.

force = mass x acceleration

work = mass x acceleration x diastance

use acceleration of gravity in this problem

W (J) = m (kg) x a (m/s/s) x d (m)
W = 78 x 9.8 x 6
W = 4586.4

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A 0.500 kg rock is whirled in a vertical circle of a radius 0.60 m . the velocity of the rock at the bottom of the swing is 4.0

OLEGan [10]

Explanation:

Centripetal acceleration is:

a = v² / r

a = (4.0 m/s)² / 0.60 m

a = 26.6 m/s²

7 0

3 years ago

A hotel elevator ascends 200m with maximum speed of 5m/s. Its acceleration and deceleration both have a magnitude of 1.0m/s2. Pa

ValentinkaMS [17]

Answer:

45 s .

Explanation:

The accelerator will first accelerate , then move with uniform velocity and at last it will decelerate to rest .

displacement s = ?

acceleration a = 1 m /s²

Final speed v = 5 m/s

initial speed u = 0

v² = u² + 2as

5² = 0 + 2 x 1 x s

s = 12.5 m

B) Let time of acceleration or deceleration be t

v = u + a t

5 = 0 + 1 t

t = 5 s

Similarly displacement during deceleration = 12.5 m

Total distance during uniform motion = 200 - ( 12.5 + 12.5 ) = 175 m .

velocity of uniform motion = 5 m /s

time during which there was uniform velocity = 175 / 5 = 35 s

Total time = 5 + 35 + 5 = 45 s .

4 0

3 years ago

In as small room fan of rating 50 watt is used for 10hrs 2bulb of rating 10v are used for 8hrs daily.calculate monthly. electric

worty [1.4K]

Answer:

The electric bill for June is Rs198000

Explanation:

Convert volt to watt, but in order to do so I need to know the amps and since it is not provided I converted if the amps was 1.

I multiple 50 with 10 then with 30 so I know how much watt the fan takes at June.

Since there are 2 light bulb I multiple 10 with 2 than with 8 than with 30.

15000 watts for the fan,

4800 watts for light bulb,

add them and then times it by 10.

Rs198000

4 0

3 years ago

Please help with these questions. All questions are in the image.

S_A_V [24]

1) Average speed

2) Displacement

Explanation:

Speed is a scalar quantity which gives a measure of how fast a body is moving. It is equal to the ratio between the distance travelled by an object and the time taken to cover that distance:

$speed = \frac{d}{\Delta t}$

where

d is the distance covered

$\Delta t$ is the time taken

It is important to note that being a scalar, speed does not have any direction. Moreover, distance is also a scalar quantity, which corresponds to the total length of the path covered by the object, regardless on the direction taken.

So, the equation "travelled distance/elapsed time" corresponds to the average speed. (where the term average refers to the fact we are not measuring the speed at a specific instant in time, but on a certain time interval $\Delta t$ .

Velocity is a vector quantity, so it has both a magnitude and a direction.

The magnitude of the velocity is given by:

$velocity=\frac{\Delta x}{\Delta t}$

where

$\Delta x$ is the change in position (or displacement) of the object

$\Delta t$ is the time taken

And the direction of the velocity corresponds to the direction of the displacement.

We must note that while distance does not depend on the direction, displacement does. In fact, displacement measures the difference between the initial and final position of the object.

Therefore, the equation "change in position / elapsed time" is equal to the average velocity.

Learn more about speed and velocity:

brainly.com/question/8893949 (speed)

brainly.com/question/5063905 (speed vs velocity)

brainly.com/question/5248528 (velocity)

#LearnwithBrainly

4 0

3 years ago

Mary travelled 70 miles/hour due north. This is an example of what?

kolezko [41]

I believe this would be an example of Mary's velocity. We have her speed and direction which is all you need to find velocity.

4 0

3 years ago

Read 2 more answers