Speed is different from velocity. Velocity is a vector quantity and has a direction. Speed is a scalar quantity and does not require a direction. The answer must be D).

**Explanation:**

The concentration of salt after t minutes is given by :

A tank contains 9000 L of pure water. Brine that contains 40 g of salt per liter of water is pumped into the tank at a rate of 25 L/min.

**We need to find the concentration approach at**

So,

Put

Since,

**C(t) = 40 g/L**

**So, at the concentration approaches to 40 g/L. Hence, this is the required solution.**

**Answer:**

**V_c=5.037 m/s**

**Explanation:**

**SOLUTION:**

applying the conversation of energy, taking the datum at B

V_b=(m_c+m_b)gh_a=(3+0.5)*9.81*0=0 J

**V_b=4.95 m/s**

applying the conversation of linear momentum,

(m_c+m_b)V_b=m_c*V_c+m_b*V_b

**V_b=6*V_c-34.66 ** **(1)**

**utilising the relative velocity relation,**

V_b/c=V_b-V_c

**V_b=0.6-V_c (2)**

from (1) (2)

6*V_c-34.66=0.6-V_c

7*V_c=35.26

the final velocity of the cart is

**V_c=5.037 m/s**

into **(2)**

**V_b=0.6-V_c **

**V_b=0.6-5.037 **

** = 4.437**

** **

Hi there my friend :)

Your answer is C. frequency

Hope this helps :)

-xxAnsxx-

**Answer:**

v = 2.94 m/s

**Explanation:**

Given that,

Mass of anvil, m = 15 kg

The gravitational potential energy relative to the floor, P = 65 J

We need to find the speed just before it hits the floor when the Anvil is released. Let it is v.

We can use the conservation of energy.

**So, the required speed is 2.94 m/s.**