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3 years ago

What is meant by pressure?write its unit.

Physics

1 answer:

Mars2501 [29]3 years ago

5 0

Answer:

Pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distributed

Unit: Pascal (Pa)

1Pa = 1N/m^2

You might be interested in

State the relation between acceleration and momentum

polet [3.4K]

Answer:

Acceleration is the rate of change in velocity. Momentum is the mass times the velocity. So if you multiply the mass times the acceleration, you get the of change of momentum.

8 0

3 years ago

I place an ice cube with a mass of 0.223 kg and a temperature of −35◦C is placed into an insulated aluminum container with a mas

Nadya [2.5K]

To solve this problem it is necessary to use the calorimetry principle. From the statement it asks about the remaining ice, that is, to the point where the final temperature is 0 ° C.

We will calculate the melted ice and in the end we will subtract the total initial mass to find out how much mass was left.

The amount of heat transferred is defined by

$Q = mc\Delta T$

Where,

m = mass

c = Specific heat

$\Delta T =$ Change in temperature

There are two states, the first is that of heat absorbed by that mass 'm' of melted ice and the second is that of heat absorbed by heat from -35 ° C until 0 ° C is reached.

Performing energy balance then we will have to

$Q_i-E_h = Q_m$

Where,

$Q_ i$ = Heat absorbed by whole ice

$Q_m$ = Heat absorbed by mass

$E_h$ = Heat energy by latent heat fusion/melting

$m_i*c_i \Delta T +m*L_f = (m_wc_w+m_{al}c_{al})\Delta T$

Replacing with our values we have that

$0.223*2108(-(-35))+m*3.34*10^5 = (0.452*4186+0.553*902)(27-0)$

$16452.9+334000m = (1892.072+498.806)*27$

Rearrange and find m,

$m = 0.144Kg$

Therefore the Ice left would be

$m' = 0.223-0.144$

$m' = 0.079Kg$

Therefore there is 0.079kg ice in the containter when it reaches equilibrium

8 0

3 years ago

Calculate the work function that requires a 475 nm photon to eject an electron of 1.25 eV.

lapo4ka [179]

The work function has the formula
E = h v

where
E is the energy
h is the constant
v is the frequency

Since the given is wavelength, we use the relationship between frequency and wavelength
v = c / λ
where
c is the speed of light
λ is the wavelength

So.
E = h c / λ
h = Eλ / c = 1.25 eV (475x10-9m) / (3x10^8 m/s)
h = 1.9792 x 10^-15

The work function is:
E = 1.9792 x 10-15 v

3 0

3 years ago

Person is lifting a 250 N dumbbell. The weight is 30 cm from the pivot point of the elbow. What force must be exerted five from

qwelly [4]

Refer to the diagram shown below.

The force, F, is applied at 5 cm from the elbow.

For dynamic equilibrium, the sum of moments about the elbow is zero.
Take moments about the elbow.
(5 cm)*(F N) - (30 cm)*(250 N) = 0
F = (30*250)/5 = 1500 N

Answer: 1500 N

4 0

3 years ago

2. A common physics experiment involves lowering an open tube into a cylinder of water and moving the tube up and down to adjust

notsponge [240]

Answer:

Explanation:

This question pertains to resonance in air column. It is the case of closed air column in which fundamental note is formed at a length which is as follows

l = λ / 4 where l is length of tube and λ is wave length.

here l = .26 m

λ = .26 x 4 = 1.04 m

frequency of sound = 330 Hz

velocity of sound = frequency x wave length

= 330 x 1.04

= 343.2 m /s

b )

Next overtone will be produced at 3 times the length

so next length of air column = 3 x 26

= 78 cm

c )

If frequency of sound = 256 Hz

wavelength = velocity / frequency

= 343.2 / 256

= 1.34 m

= 134 cm

length of air column for resonance

= wavelength / 4

134/4

= 33.5 cm

7 0

3 years ago