An engine pumps water continuously through a hose. Water leaves the hose with a velocity of 2 m/sand the mass per unit length of the water jet is 0.1 kg/m. What is the power of the engine?

B. 0.4 W — Power is the rate of change of kinetic energy. The mass flow rate is lambda times velocity, and kinetic energy per unit time is 0.5 * dm/dt * v^2.

JEE Main · PhysicsMedium

$An engine pumps water continuously through a hose. Water leaves the hose with a velocity of v = 2 m/s and the mass per unit length of the water jet is λ = 0.1 kg/m . What is the power of the engine?$

A. $0.2 W$
B. $0.4 W$
C. $0.8 W$
D. $0.1 W$

Show correct answer & step-by-step solution

Correct answer: B — $0.4 W$

Solution

Mass flow rate d m / d t = λ v = 0.1 \times 2 = 0.2 kg/s . Power P = 0.5 \times (d m / d t) \times v^{2} = 0.5 \times 0.2 \times 4 = 0.4 W .

Attempt this question & track your score

Attempt & Track Free →

More Work Energy Power practice questions

$A force of 10 Newtons acts on a body and displaces it by 5 meters in the direction of the force. Calculate the work done$
$A body of mass 2 kg is moving with a velocity of 4 meters per second. What is its kinetic energy in Joules?$
$An object of mass 5 kg is raised to a height of 10 meters above the ground. Calculate the potential energy gained by the$
$A machine does 400 Joules of work in 20 seconds. What is the power of the machine in Watts?$
$If the velocity of a body is doubled, its kinetic energy becomes how many times its original value?$
$A p a r t i c l eo f ma ss 2 k g m o v es u n d er t h e in f l u e n ceo f a f or ce F = (3 t^{2} i + 4 t j) N . I f t h e p a r t i c l es t a r t s f r o m r es t a t$
$A block of mass 1 kg is pushed against a spring with spring constant 100 N/m, compressing it by 0.2 m. When released, th$
$A body of mass 2 kg is dropped from a height of 10 meters. Due to air resistance, it hits the ground with a speed of 12$
$A force F = (2x + 3) N acts on a particle moving along the x-axis. What is the work done by this force as the particle m$
$An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit le$
$A p a r t i c l eo f ma ss mm o v es ina p o t e n t ia l f i e l d U (x) = a / x^{2} - b / x, w h er e aan d ba r e p os i t i v eco n s t an t s . W ha t i s t h e p e$
$A block of mass m is attached to a spring of constant k and is placed on a rough horizontal surface with coefficient of$

View all Work Energy Power questions →

An engine pumps water continuously through a hose. Water leaves the hose with a velocity of v=2 m/s and the mass per unit length of the water jet is λ=0.1 kg/m. What is the power of the engine?

Solution

Attempt this question & track your score

More Work Energy Power practice questions

$An engine pumps water continuously through a hose. Water leaves the hose with a velocity of v = 2 m/s and the mass per unit length of the water jet is λ = 0.1 kg/m . What is the power of the engine?$