Question

For calculating work, the force and the distance must be in the same ____________. Units direction magnitude 2. The lawnmower handle is at an angle to make it _________ to push. Easier harder 3. What units for time must be used in calculating power? Days hours seconds

Answer 1

Answer: 1.) Direction

2.) Easier

3.) Seconds

Explanation:

1.) Work is defined as the scalar product of force and distance. The force is applied in the same direction as that of distance.

Mathematically,

$W=F.s=Fs(cos\theta)$

2.) From the above expression, the angle plays an important role in the calculation of work.

When $\theta =0\°$, then $cos\theta =1$ and work done will be maximum in that case.

But, when the angle increases, the magnitude of work decreases and it becomes easier to push.

When $\theta =90\°$, then $cos\theta =0$ and work done will be 0 which is minimum.

3.) Expression for power is given as:

$Power=\frac{Work}{Time}$

$\text{Unit of power = Watt = }\frac{Joules}{Seconds}$

Units of time which must be used in calculating power is seconds.