Answer:
Option D
Explanation:
The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.
In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.
In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.
Answer:
342 m/s
Explanation:
The velocity of sound in air is approximated as:
v ≈ 331.4 + 0.6 T
where v is the velocity in m/s and T is the temperature in Celsius.
At T = 18:
v ≈ 331.4 + 0.6 (18)
v ≈ 342.2
The velocity is approximately 342 m/s.
Answer:
0.43 m
Explanation:
Angle of incident and angle of reflection is same.
tan Θh = L' / x (eye)
L' = Length of the window
x (eye) = Distance of the mirror from the eye
tan Θh = L / (x (eye) + xw)
xw = Distance of the mirror from the window
L'/ x (eye) = L / ( x (eye) + xw)
L' = L*x (eye) / ( x (eye) + xw)
L' = (2*0.5) / (0.5 + 1.8)
L' = 0.43 m
Answer:
3a, 2b,4c,1d
Explanation:
what do I need to explain just something you know
