Question

We have an electric kettle rated at (60v, 5A). We have a mass of 10 kg that is placed such that the steam in the kettle is used to drive the mass in the horizontal direction.If the kettle runs for 5 minutes.What is the velocity of mass attained?

• A. 100 m/s
• B. 50 m/s
• C. 60√20 m/s
• D. 30√20 m/s

Answer 1

The correct option is D

30√20 m/s

The energy used by kettle is = VIt = 60 $\times$ 5 $\times$ 5 $\times$ 60 = 90000 Ws = 90000 J
Now,This energy is used to drive the ball.

$\Rightarrow$ 90000 = $\frac{1}{2}$​ $\times$ m $\times$ $v^2$​

$\Rightarrow$ $v^2$​​ = $\frac{90000\times 2}{10}$

v = $\sqrt{18000}$

v = 30$\sqrt{20}$ $\frac{m}{s}$

v = 60$\sqrt{5}$ $\frac{m}{s}$