The correct answer to the question is : D) 352.6 m/s.
CALCULATION :
As per the question, the temperature is increased from 30 degree celsius to 36 degree celsius.
We are asked to calculate the velocity of sound at 36 degree celsius.
Velocity of sound is dependent on temperature. More is the temperature, more is velocity of sound.
The velocity at this temperature is calculated as -
V = 331 + 0.6T m/s
= 331 + 0.6 × 36 m/s
= 331 + 21.6 m/s
= 352.6 m/s.
Here, T denotes the temperature of the surrounding.
Hence, velocity of the sound will be 352.6 m/s.
Answer:
3136 Joules
Explanation:
Applying,
P.E = mgh.............. Equation 1
Where P.E = potential energy, m = mass of the cinder block, h = height of the platform, g = acceleration due to gravity.
From the question,
Given: m = 16 kg, h = 20 m
Constant: g = 9.8 m/s²
Substitute these values into equation 1
P.E = 16(20)(9.8)
P.E = 3136 Joules
Hence the potential energy of the cinder block is 3136 Joules
Answer:
(A) -2940 J
(B) 392 J
(C) 212.33 N
Explanation:
mass of bear (m) = 25 kg
height of the pole (h) = 12 m
speed (v) = 5.6 m/s
acceleration due to gravity (g) = 9.8 m/s
(A) change in gravitational potential energy (ΔU) = mg(height at the bottom- height at the top)
height at the bottom = 0
= 25 x 9.8 x (0-12) = -2940 J
(B) kinetic energy of the Bear (KE) = 
= 
= 392 J
(C) average frictional force = 
- change in KE (ΔKE) = initial KE - final KE
- ΔKE = -
- when the Bear reaches the bottom of the pole, the final velocity (Vf) is 0, therefore the change in kinetic energy becomes ΔKE =
- 0 = 392 J
\frac{-(ΔKE+ΔU)}{h}[/tex] = 
= 
= 212.33 N
Friction can be bad by being too strong or too weak.
<span>Sometimes, when it is too strong, it decreases efficiency since some energy is wasted and turns to heat. Friction can also d</span><span>amage equipment/objects like when you slide it on the floor.
</span>
When friction is too weak, like for instance when there is black ice- our center of gravity is displaced too quickly and we can fall. Likewise, if there is a lot of slush on the ground, cars can slip and slide.
