20.9m = 1s
286.33m = 13.7s
To answer this you would multiply both sides by the amount of seconds she ran. The answer however is that she ran as far as 286.33m.
Answer:
a) the frequency of the wave is 0.2 Hz
b) the speed of the wave 4 m/s
Explanation:
Given that;
time period = to complete one cycle t = 5 sec
frequency f = 1/t
frequency f = 1 / 5sec
f = 0.2 Hz
Therefore the frequency of the wave is 0.2 Hz
b)
speed of wave V = λf
given that our wavelength is 20.0 m
we substitute
speed of wave V = 20.0 × 0.2
speed of wave V = 4 m/s
Therefore, the speed of the wave 4 m/s
When car is at the top of the hill its whole energy is stored in the form of gravitational potential energy
so when height of the car becomes half then its potential energy is given as
so final potential energy when car falls down by half of the height will become half of the initial potential energy
So it is U = 50 MJ after falling down
Now by energy conservation we can say that final potential energy + final Kinetic energy must be equal to the initial potential energy of the car
So here at half of the height kinetic energy of car = 100 - 50 = 50 MJ
so we can say at this point magnitude of potential energy and kinetic energy will be same
<em>A. the same as the potential energy at that point.</em>
Answer:
Option b
Explanation:
An object is said to fall freely when there is no force acting on the object other than the gravitational force. Thus the acceleration of the object is solely due to gravity and no other acceleration acts on the body.
Also the initial velocity of the body in free fall is zero and hence less than the final velocity.
As the body falls down closer to earth, it experiences more gravitational pull and the velocity increases as it falls down and the moment it touches the ground the period of free fall ends at that instant.
Thus the final velocity of an object in free fall is not zero because the final velocity is the velocity before coming in contact with the ground.
Answer:
B) alternating current
Explanation:
Alternating currents are different from direct current. These form of currents are used to transport power from generating stations over large distances.
- Alternating current is a current that reverses direction periodically.
- The voltage also reverses and leads to little loss in voltage.
- This current reversal makes them desirable for long distance transmission coupled with the little loss in voltage.
- Transformers used to change the voltage of these wave forms.
- The lesser loss in voltage makes AC desirable for long distance transmission.