Answer:

Explanation:
Given that
Train 1 (observer):
Speed = 109 km/h
Train 2 (source):
Speed = 99 km/h
Train 2 emitting frequency = 500 Hz
We know that observer and source are moving toward each other, then frequency heard by observer can be given as follows

Where C is the velocity of sound (C=1225 Km/h)
Now by putting the values



Answer:
Magnitude of C= 
Angle=arctan(Ay+By/Ax+Bx)
Explanation:
Let
A = Axi + Ayj
B = Bxi + Byj
where i and j are unit vectors in the direction of x and y axes respectively.
C=A+B
C = (Ax + Bx)i + (Ay + By)j
The magnitude of vector C can be calculated by adding the square of magnitude of its componets and then taking sqaure root.
Magnitude of C= 
And the angle will be
Angle=arctan(Ay+By/Ax+Bx)
Electrons are negatively charged so an excess will produce a negative charge.
Since acceleration is measured in whole seconds, you need to know how many times 0.157seconds goes into 1 second... (just divide 1 by 0.157) = 6.369
So if in 0.157seconds the baseball went from zero to 38m/s, then to find out how fast it would be traveling after one whole second just multiply 38m/s by 6.369
38m/s x 6.369 = 242.038 m/s^2
Answer:
Option d and e are correct.
Explanation:
The expression for velocity of pulse in a stretched string can be given as follows
v = 
where T is tension in the string , m is mass of string per unit length.
Use of lighter string of the same length, under the same tension amounts to higher m so velocity will decrease. Hence option d is correct.
Similarly, v is directly proportional to square root of tension. So if we increase tension , velocity also increases. So option e ) is correct.