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3 years ago

25 POINTS

Physics

2 answers:

Vladimir79 [104]3 years ago

6 0

There is a physical change I think

Alexandra [31]3 years ago

4 0

pshyical change is a usually reversible change of a substance, as size or shape: Freezing a liquid is a physical change. Compare chemical change.

internal change is when the movement of the particles increases

specific latent heat is the amount of energy per kg (unit mass) required to change ice to water without change in temperature.

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A ball starts from rest and undergoes uniform acceleration of 2.50m/s^2. What is the velocity of the ball 4s later?

erica [24]

Explanation:

Given:

v₀ = 0 m/s

a = 2.50 m/s²

t = 4 s

Find: v

v = at + v₀

v = (2.50 m/s²) (4 s) + 0 m/s

v = 10 m/s

4 0

3 years ago

Read 2 more answers

Consider an object rolling off of your lab bench. Discuss how you might be able to make measure- ments to determine its initial

guapka [62]

Answer:

measure the position every so often with a stopwatch

Explanation:

A possible method of measurement is to place a measuring tape along the path and measure the position every so often with a stopwatch, with this we can make a graph of position against time and by extrapolation find the initial velocity.

This is a method used in measurements of uniform movements of bodies

7 0

3 years ago

A gymnast dismounts off the uneven bars in a tuck position with a radius of 0.3m (assume she is a solid sphere) and an angular v

kifflom [539]

Here we will say that there is no external torque on the system so we will have

$L_i = L_f$

here we know that

$L_i = I_1\omega_1$

where we know that

$I_1 = \frac{2}{5}mr^2$

Also we know that

$I_2 = \frac{1}{12}mL^2$

initial angular speed will be

$\omega_1 = 2\pi(2rev/s) = 4\pi rad/s$

now from above equation

$\frac{2}{5}mr^2 (4\pi) = \frac{1}{12}mL^2 \omega$

$0.4(0.3)^2(4\pi) = \frac{1}{12}(1.5)^2\omega$

$0.452 = 0.1875 \omega$

now we have

$\omega = 2.41 rad/s$

so final speed will be 2.41 rad/s

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3 years ago

A closed system consisting of 2 lb of a gas undergoes a process during which the relation between pressure and volume is pVn = c

vazorg [7]

Answer:

V1=2.5ft3

V2=1ft3

n=1.51

Explanation:

PART A:

the volume of each state is obtained by multiplying the mass by the specific volume in each state

V=volume

v=especific volume

m=mass

V=mv

state 1

V1=m.v1

V1=2lb*1.25ft3/lb=2.5ft3

state 2

V2=m.v2

V2=2lb*0.5ft3/lb= 1ft3

PART B:

since the PV ^ n is constant we can equal the equations of state 1 and state 2

P1V1^n=P2V2^n

P1/P2=(V2/V1)^n

ln(P1/P2)=n . ln (V2/V1)

n=ln(P1/P2)/ ln (V2/V1)

n=ln(15/60)/ ln (1/2.5)

n=1.51

8 0

3 years ago

Proyektil dengan massa 10 gram ditembak dari senapan dengan massa 5 kg. Kecepatan proyektil sesaat setelah memotret dari laras a

notka56 [123]

Answer:

-0.4 m/s

Explanation:

According to the law of conservation of momentum, the total momentum of the bullet - rifle system must be conserved.

The total momentum before the shot is zero, since they are both at rest:

$p_i = 0$

While the total momentum after the shot can be written as:

$p_f = mv+MV$

where

m = 10 g = 0.010 kg is the mass of the bullet

M = 5 kg is the mass of the rifle

v = 200 m/s is the velocity of the bullet

V is the recoil velocity of the rifle

Since the total momentum is conserved, we can write:

$p_i = p_f$

$0=mv+MV$

And solving for V, we find the recoil velocity:

$V=-\frac{mv}{M}=-\frac{(0.010)(200)}{5}=-0.4 m/s$

and the negative sign indicates that the velocity is opposite to the bullet.

7 0

3 years ago