Answer:
option(d)
Explanation:
The frequency of a wave is the property of the source of wave.
The velocity of all the electromagnetic waves is same as the speed of light. It only changes as the light passes through one medium to another.
The frequency is defined as the number of waves coming out from the source in 1 second.
As the frequency of wave increases, the number of wave coming per second increases.
So, the number of waves passing by increases but the speed remains same.
Option (d)
Average velocity = (displacement) / (total time)
Displacement = distance and direction between
the starting point and the end point
The car travels 90 meters north, then 40 meters south.
So it ends up 50 meters north of where it began.
Displacement = 50 meters north
Total time = (15 + 5) = 20 seconds
Average velocity = (50 meters north) / (20 seconds)
= 2.5 m/s north
Answer:
False
Explanation:
The magnitude of any vector is given by,

The magnitude of anything is never negative. It can be even seen from the formula that the components are squared. A squared value can never be negative. Even if the component is negative the square will be always positive.
So, magnitude of the vector is <u>not</u> negative.
Answer:
Explanation:
During rescue missions, different types of energy can be devices for flashlight, this could be human powered energy such as squeezing or compressing. In flashlight electrical energy is converted to light and thermal energy.
A squeezing or compressing to get energy for flashlight can be regarded as "DYNAMO PROCESS" it involves spinning of "fly wheels" into the flashlight through consistent squeezing ,which is connected to a dynamo(Dynamo supply electrical current). Hence the needed light is seen on the bulb of the flashlight.
Answer:
v = 3.04 m/s
Explanation:
given,
mass of the block, M = 6.6 Kg
horizontal force, F = 12.2 N
distance, L = 2.5 m
initial speed = 0 m/s
speed of the block,v = ?
we now
Work done is equal to change in Kinetic energy.
Work done = Force x displacement
W = Δ K E
Δ K E = Force x displacement


3.3 v² = 30.5
v² = 9.242
v = 3.04 m/s
speed of the block is equal to 3.04 m/s