How many watt-hours does a 80 watt light bulb use if it runs for 3.5 hours?

A ball with a weight of 2 N is attached to the end of a cord of length 2m . The ball is whirl in a vertical circle counterclockw

ZanzabumX [31]

Answer:

we agree with

Edgar: The net force on the ball at the top position is 9 N. Both the tension and the weight are acting downward so you have to add them.

Explanation:

Weight of the ball is given as

$W = 2N$

so we have

$m = \frac{W}{g}$

$m = 0.204 kg$

now tension force at the top is given as

$T_{top} = 7 N$

$T_{bottom} = 15 N$

Now at the top position by force equation we can say that ball will have two downwards forces

1) Tension force

2) Weight of the ball

so net force on the ball is given as

$F_{net} = T + W$

$F_{net} = 7 + 2 = 9 N$

So we agree with

Edgar: The net force on the ball at the top position is 9 N. Both the tension and the weight are acting downward so you have to add them.

8 0

3 years ago

How high can a 40 N force move a load, when 395 J of work is done?

Juliette [100K]

Answer:

9.875

Explanation:

w=f×s

395=40×s

make s the subject of the formula

s=395/40

=9.875

7 0

3 years ago

How fast is a wave traveling if it has a wavelength of 7 meters and a frequency of 11 Hz?

pashok25 [27]

Answer:

$\huge{ \boxed{ \bold{ \sf{77 \: m/s}}}}$

☯ Question :

How fast is a wave travelling if it has a wavelength of 7 meters and a frequency of 11 Hz?

☯ $\underbrace{ \sf{Required \: Answer : }}$

☥ Given :

Wavelength ( λ ) = 7 meters
Frequency ( f ) = 11 Hz

☥ To find :

Speed of sound ( v ) = ?

☄ We know ,

$\boxed{ \sf{v = f \times λ}}$

where ,

v = speed of sound
f = frequency
λ = wavelength

Now, substitute the values and solve for v.

➺ $\sf{v = 11 \times 7}$

➺ $\boxed{ \sf{v = 77 \: m/s}}$

-------------------------------------------------------------------

✑ Additional Info :

Frequency : The number of complete vibrations made by a particle of a body in one second is called it's frequency. It is denoted by the letter f . The SI unit of frequency is hertz ( Hz ).

Wavelength : The distance between two consecutive compressions or rarefactions of a sound wave is called wavelength of that wave. It is denoted by λ ( lambda ) and it's SI unit is m.

Speed of a sound wave : The distance covered by a sound wave in one second is called speed of sound wave. It depends on the product of wavelength and frequency of the wave.

Hope I helped!

Have a wonderful time! ツ

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7 0

3 years ago

A washing machine heats 10kg of water in each wash cycle. How much energy is saved by washing at 30'c instead of 50'c if the sta

Volgvan

The equation for this is very simple you add then you subtract then you get the answer then you divide then it all works out for you

6 0

3 years ago

An airplane during departure has a constant acceleration of 3 m / s².

Rama09 [41]

Constant acceleration of plane = 3m/s²

a) Speed of the plane after 4s

Acceleration = speed/time

3m/s² = speed/4s

S = 12m/s

The speed of the plane after 4s is 12m/s.

b) Flight point will be termed as the point the plane got initial speed, u, 20m/s

Find speed after 8s, v

a = 3m/s²

from,

a = v - u

t

3 = v - 20

8

24 = v - 20

v = 44m/s

After 8s the plane would've 44m/s speed.

6 0

2 years ago