Explanation:
here,load=100N
effort=200N
distance travelled by load=2cm
distance travelled by effort=10cm
Now, output work=L*Ld
=100*2
=200g
Again,
input work =E*Ed
200*10
2000j
again, efficiency = output work/input work*100%
200/2000*100%
=10%
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The original frequency of horn of Car A is 1071 Hz.
Explanation:
Doppler effect describes the change in the frequency of sound waves with respect to the observer. As the sound waves emitted from a source need to travel the air medium to reach observer, it will undergo loss in energy. So there will be change in its frequency compared to original frequency. Depending upon the direction of travel of source and observer the shifting of frequency will vary.

Here vo is the observer velocity and vs is the velocity of the source. So Vo = 15 m/s as car B is the observer and Vs = 35 m/s as car A is the source. And f is the frequency of sound wave at source that is car A.
Similarly, the doppler shift in frequency is the frequency of sound heard by car B which is f' = 1140 Hz. And v is the speed of sound that is v = 343 m/s
1140 = 
f = 1140/1.0649= 1071 Hz.
Thus, the original frequency of horn of Car A is 1071 Hz.
There are no appropriate units for power on the list you provided
Answer:
option B
Explanation:
Radius of new planet,R' = 2R
Mass of the earth, M' = 2 M
R and M is the Radius and Mass of the earth.
Weight of the person on earth = 500 N
Weight of the person in the new planet = ?
We know acceleration due to gravity is calculated by using formula

now, acceleration due to gravity on the new planet




here acceleration due to gravity is half in new planet, so weight will also be half on the new planet.
Weight on the new plane is equal to
= 250 N
correct answer is option B
Answer:
Explanation:
Balance force ( W ) = 85 N
a) moving upward with constant velocity (V ) = 7.9 m/s.
The reading will not change since it is moving with constant velocity
W = 85 N
b) Moving upward with V = 7.9 m/s and decelerating at the rate of (a ) = 1.1 m /s²
The net force ( F ) = W - ma
where m = W/g = 85/9.81 = 8.6646 kg
F = 85 - 8.6646 * 1.1 = 75.4689 N