Also B. Water is the solvent is correct
Answer:
Explanation:
Impulse of reaction force of floor = change in momentum
Velocity of impact = √ 2gh₁
= √ 2 x 9.8 x 1.5 = 5.4 m /s.
velocity of rebound = √2gh₂
= √ 2x 9.8 x 1
= 4.427 m / s.
Initial momentum = .050 x 5.4 = .27 kg m/s
Final momentum = .05 x 4.427 = .22 kg.m/s
change in momentum = .27 - .22 = .05 kg m/s
Impulse = .05 kg m /s
Impulse = force x time
force = impulse / time
.05 / .015 = 3.33 N.
kinetic energy = 1/2 m v²
Initial kinetic energy = 1/2 x .05 x 5.4²
= 0.729 J
Final Kinetic Energy =1/2 x .05 x 4.427²
= 0.489 J
Change in Kinetic energy =0 .24 J
Lost kinetic energy is due to conversion of energy into sound light etc.
In the question it is already given that the football player is 80 kg.
Then the mass of the football player = 80 kg
Velocity at which the football player is running = 8 m/s
<span>Kinetic Energy = 0.5 • mass • square of velocity
Now we have to put the known data in this equation to find the actual velocity of the footballer.
</span> <span></span>So
Kinetic Energy of the footballer = 0.5 * 80 * (8 * 8)
= 0.5 * 80 * 64
= 2560
So the Kinetic energy of the footballer is 2560 joules
Answer is C is the correct answer
Answer:
the electric field direction should be in positive y axis
Explanation:
Lets assume that charge on particle is positive and it isequal to +q
First calculate the magnetic force on it
for direction
use Right Hand Rule which will give the direction and by using his the direction will come towards negative y axis.
As given in the question that charge particle does not change their velocity so we need to apply electric field in such a way that electric force direction should be opposite to the magnectic field.
and magnitude should be same as magnectic force and also direcion of electric force depend on the direction of elecric field when charge is positive because electric force 
Hence the electric field direction should be in positive y axis
