Answer:
0.031 W
Explanation:
The power used is equal to the rate of work done:

where
P is the power
W is the work done
t is the time taken to do the work W
In this problem, we have:
W = 900 J is the work done by the motor
t = 8 h is the time taken
We have to convert the time into SI units; keeping in mind that
1 hour = 3600 s
We have

And therefore, the power used is

Answer:
d = 90 ft
Explanation:
As we know that after each bounce it reaches to 4/5 times of initial height
so we can say

so the distance covered is given as

here we know that
h = 10 feet



Answer:
10miles/second
Explanation:
Change in velocity of the bird is expressed as the difference between the final velocity and initial velocity of the body.
Change in velocity = Final velocity - initial velocity
Since the bird takes off from the tree, the initial velocity of the bird = 0miles/sec
Final velocity = 10miles/secs
Change in velocity = 10-0
Change in velocity = 10miles/second
Answer:

Explanation:
The acceleration of the block can be found by the kinematics equations:

Since the plane is frictionless, the only force acting on the block along the motion of the block is its weight.
