Question

A woman pushes a lawn mower with a constant force of 112 Newtons at an angle of 37◦ with respect to the horizontal. The lawn mower moves at a speed of 20 cm/sec. What is her power output? (1 hp = 746 Watts)
1. 0.024 hp
2. 0.030 hp
3. 0.020 hp
4. 0.040 hp
5. 0.044 hp
6. 0.034 hp

Answer 1

Answer:

1.0.024 hp

Step-by-step explanation:

We are given that

Constant force=F=112 N

$\theta=37^{\circ}$

Speed of lawn mower,v=20 cm/s=$20\times 10^{-2} m/s$

1 m=100 cm

1 hp=746 watt

We have to find the power output

Force applied by women on lawn mower=$Fcos\theta=112cos 37^{\circ}$

Force applied by women on lawn mower=$89.45$N

Power output,P=$Fv$

Using the formula

Power output=$89.45\times 20\times 10^{-2}=17.89 watt$

Power output,P=$\frac{17.89}{746}=0.024$hp

Hence, option 1 is true