Hypothesis: When the container with the balloon and plaster of Paris is placed in the freezer, the water inside the balloon will freeze and expand as it turns into ice. As the water freezes, it will exert pressure on the plaster, causing the plaster to crack or deform. The extent of cracking or deformation may depend on the strength and thickness of the plaster.
Part B of the experiment would typically involve conducting the experiment and observing the actual outcome to confirm or reject the hypothesis.
B. burning fossil fuels
C. nuclear power
D. hydroelectric power
you could use SUVAT to work out the deceleration and then use F=ma
S= 79m U=28m/s V=0m/s A=? T=n/a
V^2 = U^2 + 2AS so 0 = 28^2 + 158A so -158A = 784
A= 4.962 (3dp)
so F = ma = 4.962 *1330 = 6599.494N (3dp)
slow-moving wind over smooth water
B.
slow-moving wind over choppy water
C.
fast-moving wind over smooth water
D.
fast-moving wind over choppy water
The object be going at the bottom of the hill with velocity 7.75 m/s.
When an item is moving, its velocity is the rate at which its direction is changing as seen from a certain point of view and as measured by a specific unit of time.
Given in the question a 400 kg object is sitting at rest at the top of a hill that is 30.0 m high and 80.0 m long measured along the hill . If there is no friction, velocity with which object be going at the bottom of the hill,
θ =sin^-1(30/80)
θ =22
F = 400 g sin(22) = 150 N
F = ma
150 = 400 a
a = 0.375 m/s²
v² - u²= 2 a s
v² - 0 = 2 x 0.375 x 80
v = 7.75 m/s
The object be going at the bottom of the hill with velocity 7.75 m/s.
To learn more about velocity refer the link:
#SPJ2
B. 22 Hz and 42 Hz
C. 47 Hz and 55 Hz
D. 18 Hz and 26 Hz
Answer:
B. 22 Hz and 42 Hz
Explanation:
The beat is an interference pattern which occurs when two waves of slightly different frequencies meet each other. The beat is heard as a periodic variation, whose frequency (called beat frequency) is equal to the absolute value of the difference between the frequencies of the individual waves:
In this problem, we are told that 20 beats per second are produced, so the beat frequency is
Therefore, we must find the two waves which have a difference in frequency equal to this value, 20 Hz. Let's see each choice:
A. 38 Hz and 63 Hz --> --> NO
B. 22 Hz and 42 Hz --> --> YES
C. 47 Hz and 55 Hz --> --> NO
D. 18 Hz and 26 Hz --> --> NO
So, the correct choice is
B. 22 Hz and 42 Hz