Answer:
Given that,
- Power = 2000 W
- time = 60 seconds
- distance= 10m
Power = work done ÷ time
Here, since the movement is vertical, w = mgh
So,
Power = mgh÷t
2000 = (m × 9.8 ×10) ÷ 60
m = (2000 ×60) ÷98
m = 1224.5kg
Answer:
Reflection involves a change in direction of waves when they bounce off a barrier. Refraction of waves involves a change in the direction of waves as they pass from one medium to another.
During that period of time, the bird's displacement was 4 km east. So its velocity was (4km east)/(11hrs). That's 0.36 km/hour east. (rounded)
Answer:
a) 
b) 
c) 
Explanation:
the gravitational potential energy is given by:


The kinetic energy is given by:

the initial kinetic energy is zero because the motion started from rest, so:

applying the conservation of energy theorem:

The work done by the friction force is given by:

the angle of the force is 180 degrees because it's against the movement:
