Answer:
Explanation:
Given a ball of mass m= 0.5kg
The ball moves in as circle of radius r= 0.4m
Speed of the ball is v = 4m/s
Centripetal force is exerted on ball and it is given as
Fc = m•ac
ac is centripetal acceleration and it is given as
ac = v²/r
Then,
Fc = mv²/r
Fc = 0.5 × 4²/0.4
Fc = 20N.
The force exerted on the ball is 20N
<u>Answer:</u> The elevation in boiling point is 1.024°C.
<u>Explanation:</u>
To calculate the elevation in boiling point, we use the equation:

where,
i = Van't Hoff factor = 2 (for NaCl)
= change in boiling point = ?
= boiling point constant = 
m = molality = 1.0 m
Putting values in above equation, we get:

Hence, the elevation in boiling point is 1.024°C.
Answer:
The option is B is not true for Hubble telescope.
Answer:
35
Explanation:
We are given that
Initial voltage,
Final voltage, 
Number of tuns in primary coil of the transformer, 
Rms current, 

We have to find the number of turns are there on the secondary coil.
We know that

Using the formula


Hence, there are number of turns on the secondary coil=35