Answer:
V = - 0.5 [m/s]
Explanation:
In order to solve this problem, we must use the principle of relative speeds. This is for an observer who is on the edge of the river he can see how the river moves to the left and the woman tries to move to the right but can not since:
![V_{total}=-3+2.5\\V_{total}=-0.5 [m/s]](https://tex.z-dn.net/?f=V_%7Btotal%7D%3D-3%2B2.5%5C%5CV_%7Btotal%7D%3D-0.5%20%5Bm%2Fs%5D)
That is, the person sees how the woman moves to the left but with avelocity of 0.5 [m/s] to the left
Answer:
F =
.
Explanation:
Gravitational force between two objects of masses
kept at a distance r is given by the formula
F = 
Here ,
= 2m
= 
Thus , F = 
F =
.
Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
Answer:
A.
Explanation:
X represents the transmitting power Modulates (amplitude or frequency am/fm), amplifies the signal, transmitting it out at whatever direction the antenna is set up for.