On your list you can easily identify by knowing which is not a chemical change.
A physical change is a change not involving the material composition of the water. e.g. (melting, solidifying, evaporation). As long as the change does not change the molecular composition of the water which is H20 it is physical change.
Answer:
The frictional force acting on the bear during the slide is 207.5 N
Explanation:
Given;
mass of beam, m = 25-kg
vertical height, h = 12 m
speed of fall, v = 6 m/s
Change in potential energy of the beam:
ΔP.E = -mgh = - 25 x 9.8 x 12 = -2940 J
Change in kinetic energy of the beam:
Δ K.E = ¹/₂mv² = ¹/₂ x 25 x (6)² = 450 J
Change in thermal energy of the system due to friction:
ΔE = - (ΔP.E + Δ K.E)
ΔE = - (-2940 J + 450 J)
ΔE = 2940 J - 450 J = 2490 J
Frictional force (in N) acting on the bear during the slide:
F x d = Fk x h = ΔE
Where;
Fk is the frictional force
Fk = ΔE/h
Fk = 2490J / 12m
Fk = 207.5 N
Therefore, the frictional force acting on the bear during the slide is 207.5 N
Answer:
Vf=27m/s
Explanation:
Vf=Vi+at
Lets substitute the known variables into the equation:
Vf=15+10×1.2
Vf=27m/s
So itll be going 27metres per second
Answer:
frequency of the first tuning fork can be 274 Hz or 266 Hz
Explanation:
Given data :
we have number of beats per second = 4
thus, it can also be written as
Beat frequency of the tuning fork, v = 4 Hz
Frequency of the tuning fork, f = 270 Hz
now, the beat frequency is actually the difference of the consecutive frequency.
thus, we have
Frequency of the first tuning fork as = 270 Hz + 4 Hz = 274 Hz
or
Frequency of the first tuning fork as = 270 Hz - 4 Hz = 266 Hz
Therefore, the frequency of the first tuning fork can be 274 Hz or 266 Hz
