Answer:3m/s

Explanation:

mass(m)=50kg

Kinetic energy =225 joules

Kinetic energy=(m x (velocity)^2)/2

225=(50 x (velocity)^2)/2

Cross multiplying we get

225x2=50x(velocity)^2

450=50x(velocity)^2

Divide both sides by 50

450/50=(50x(velocity)^2)/50

9=(velocity)^2

Taking the square root of both sides we get

√9=velocity

3=velocity

Velocity=3m/s

**Answer:**The SI system is based on the number 10 as well as multiples and products of 10. This makes it much easier to use, and so it has been the accepted system in scientific and technical applications. The English system is more complicated as relationships between units of the same quantity aren't uniform.

**Explanation:**

**Answer:**

**Magnetic field must be in YZ plane except in negative and positive Z direction.**

**Explanation:**

Here loop is in XY plane and current direction as defined then** its magnetic moment is in negative Z direction.**

- So to rotate loop about X axis force should be in plane YZ.

- Thus torque produced by this magnetic force is in direction of X axis.

Now we know torque on a loop is calculated by

**Torque=magnetic moment × B **(vector cross product)(Here B is magnetic field)

** Thus magnetic field can be in the positive and negative Y direction and Z direction.**

diagram is in attachment.

**Answer:**

**A. 19.8 cm.
**

**Explanation:**

The apparent depth of the combination is

As it mentioned that the two clear but non-mixing liquid having depth of 15 cm that placed in a glass container together

Also the refractive indices would be 1.75 and 1.33

Based on the above information

As we know that

**Refractive indices = real depth ÷ apparent depth**

1.33 ÷ 1.75 = 15 ÷ apparent depth

So, it would be 19.736842 cm

Now the combination of apparent depth would be

= ( 19.736842 + 15) ÷ (1.75)

= 19.8 cm

**hence, the correct option is A. **