Answer:
B
Explanation:
If the light is pointing down ,and then hits a surface of a 60 degree angle, then the direction will be away from the light since the light is touching a surface that is flat of a 60 degree angle then it will reflect off of it Perpendicular.
Answer:
Potential energy is
Explanation:
Given situation is shown in figure 1
In order to calculate the potential energy at the moment block started moving we first have to calculate the net force acting on the block. For this consider figure 2
<h3>Forces acting in vertical direction:</h3>
Normal force Fn acting on block is in upward direction which is balanced by horizontal component of weight of block acting in opposite direction.
<h3>Forces acting in horizontal direction:</h3>
Tension in string is equal and opposite to frictional force and and vertical component of weight as show in figure 2
Frictional force is:
From (1)
(2) becomes then
If spring is not accelerating then tension in rope must be equal spring force i.e
Then (2) becomes
Potential energy is given as
Question: A ship anchored at sea is rocked by waves that have crests 100 m apart the waves travel at 70m/S, at what frequency do the waves reach the ship?
Answer:
0.7 Hz
Explanation:
Applying,
v = λf............... Equation 1
Where v = velocity of the wave, f = frequency fo the wave, λ = wavelength of the wave
make f the subject of the equation
f = v/λ................. Equation 2
From the question,
Given: v = 70 m/s, λ = 100 m ( distance between successive crest)
Substitute these values into equation 2
f = 70/100
f = 0.7 Hz
Hence the frequency at which the wave reach the ship is 0.7 Hz
<span>The answer is none. According to the first law of Newton, an object stays at the same speed in the same direction if there are not forces unbalancing the object. Without friction, the car would be moving forever, unless there is another force accelerating or stopping the car.</span>