Answer:
D)378kJ
Explanation:
Applying,
E = F×d................ Equation 1
Where E = Energy expanded by the car, F = Wind resistance, d = distance
From the question,
F = 0.42v²............ Equation 2
Susbtitute equation 2 into equation 1
E = 0.42v²d.............. Equation 3
Given: v = 30 m/s, d = 1 km = 1000 m
Substitute these values into equation 3
E = 0.42(30²)(1000)
E = 378000
E = 378 kJ
Hence the right option is D)378kJ
Answer:
gamma ray-destruction of cancer cells
Ultraviolet wave-disruption of DNA
X-ray-diagnosis of illnesses through medical
Explanation: on edg
Answer: Frequency is 0.143 Hz; Period is 7 seconds
Explanation:
Number of vibrations = 8.6
Time required = 60 seconds
Period (T) = ?
Frequency of the vibrations (F) = ?
A) Recall that frequency is the number of vibrations that the Sears tower completes in one second.
i.e Frequency = (Number of vibrations / time taken)
F = 8.6/60 = 0.143Hz
B) Period, T is inversely proportional to frequency. i.e Period = 1/Frequency
T = 1/0.143Hz
T = 7 seconds
Thus, the frequency and period of the vibrations of the Sears Tower are 0.143 Hz
and 7 seconds respectively.
Answer:
velocity
Explanation:
velocity includes the direction taken by a person or object
