3 years ago

Can a physical change,change what a substance is? Explain your answer by giving an example.

1 answer:

7 0

No; a physical change of paper could be crumpling it up. it is still paper even if you crumple it, but youve changed its form.

You might be interested in

An object has a mass of 5.20g. The mass of the object in kg is

vampirchik [111]

Answer:

0.0520kg

Explanation:

divide by 1000

8 0

3 years ago

Tech A says that hydraulic braking systems use proportioning valves and metering valves. Tech B says that hydraulic braking syst

Finger [1]

Answer:

Option C) Both Techs A and B

5 0

3 years ago

What is a element that tends to be shiny, easy shaped, and a good conductor of heat?

ozzi

The answer to your question is Metal

8 0

3 years ago

For a home sound system, two small speakers are located so that one is 52 cm closer to the listener than the other. What is the

galina1969 [7]

Answer:

The first frequency of audible sound in the speed sound is

f = 662 Hz

Explanation:

vs = 344 m/s

x = 52 cm * 1 / 100m = 0.52m

The wave length is the distance between the peak and peak so

d = 2x

d = 2*0.52 m

d = 1.04 m

So the frequency in the speed velocity is

f = 1 / T

f = vs / x = 344 m/s / 0.52m

f ≅ 662 Hz

7 0

4 years ago

A 49 kg bear slides, from rest, 11 m down a lodgepole pine tree, moving with a speed of 3.3 m/s just before hitting the ground.

hichkok12 [17]

Answer:

a) $\Delta U_g=-5.3kJ$

b) $K=0.27kJ$

c) $F_f=0.45kN$

Explanation:

the gravitational potential energy is given by:

$U_g=m.g.h\\$

$\Delta U_g=m.g.h_f-m.g.h_i\\\Delta U_g=49kg*9.8m/s^2*(0m-11m)\\\Delta U_g=-5.3kJ$

The kinetic energy is given by:

$K=\frac{1}{2}m.v^2\\$

the initial kinetic energy is zero because the motion started from rest, so:

$K=\frac{1}{2}*49kg*(3.3m/s^2)^2\\K=0.27kJ$

applying the conservation of energy theorem:

$U_g-W_f=K_f\\W_f=-(\Delta K+\Delta U)\\W_F=5.3kJ-0.27kJ\\W_F=-5.0kJ$

The work done by the friction force is given by:

$W_f=F_f.h.cos(\theta)\\$

the angle of the force is 180 degrees because it's against the movement:

$F_f=\frac{W_f}{h.cos(\theta)}\\\\F_f=\frac{-5.0kJ}{11m.cos(180^o)}\\\\F_f=0.45kN$

8 0

4 years ago