Answer:
An electric fan is considered to be a mixture of several simple machines. It includes the Wheel and Axle type, wedges, and the Inclined plane types. The blades of an electric fan are the inclined planes and the wedges.
Gravitational Potential Energy GPE = mg∆h. 12. A 5.0 kg mass is initially sitting on the floor when it is lifted onto a table 1.15 meters high at.
Answer:
b) 900 W
Explanation:
The breaker trips when the current is equal to 20 A. The power (P) is the ddp (V) multiplied by the current. So, for the electric heater, the current is:
P = V*i
1500 = 120*i
i = 12.5 A
So, to become in 20 A, it's needed 7.5 A, which must come from the hairdryer. Its power must be:
P = 120*7.5
P = 900 W
Answer:
A. When it is in a magnetic field, it becomes a temporary magnet.
Explanation:
An iron bolt is attracted to a magnet because when in a magnetic field, the iron becomes a temporary magnet.
This is because the iron aligns their electrons in the magnetic fields.
- This causes that attraction between the magnet and the iron.
- Metals like iron are said to be ferromagnetic
- Unpaired electrons in iron spin in such a way that they align with the magnetic fields of the magnet.
Answer:The frequency of the echo is slightly decreased
Explanation:
Given
speed of boat 
cliff is 
away
when boat is still , suppose t is the time taken by the echo to reach observer on the boat
But as soon as boat starts moving the distance between cliff and boat decreasing and time for echo to reach observer also decreases
and we know 
therefore frequency of the echo slightly decreased.
