Answer:
21.8 m/s
Explanation:
At the top of the hill (crest), there are two forces acting on the motorcycle:
- The reaction force of the road, N (upward)
- The force of gravity, mg (downward)
Since the motorcycle is moving by circular motion, the resultant of these forces will give the centripetal force, so:
where the direction of the weight (mg) is equal to that of the centripetal force, and where
m is the mass of the cycle
g = 9.8 m/s^2 is the acceleration of gravity
v is the speed
r = 48.6 is the radius of the hill
The cycle loses contact with the road when the reaction force becomes zero:
N = 0
Substituting into the equation, we therefore find the maximum speed that is allowed for the cycle before losing constact:
Answer:
10 GHz
Explanation:
Applying,
v = λf.................... Equation 1
Where v = speed of microwave, λ = wavelength, f = frequency.
make f the subject of the equation
f = v/λ................ Equation 2
Note: Microwave is an electromagnetic wave, and all electromagnetic wave have the same speed, which is 3×10⁸ m/s
From the question,
Given: λ = 3 cm = 0.03 m
Constant; v = 3×10⁸ m/s
Substitute these values into equation 2
f = 3×10⁸/(0.03)
f = 10¹⁰ Hz
f = (10¹⁰/10⁹) GHz
f = 10 GHz
Answer:
The Answer is false
Explanation:
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
Answer:
B) t = 1.83 [s]
A) y = 16.51 [m]
Explanation:
To solve this problem we must use the following equation of kinematics.
where:
Vf = final velocity = 0
Vo = initial velocity = 18 [m/s]
g = gravity acceleration = 9.81 [m/s²]
t = time [s]
Note: the negative sign in the above equation means that the acceleration of gravity is acting in the opposite direction to the motion.
A) The maximum height is reached when the final velocity of the ball is zero.
0 = 18 - (9.81*t)
9.81*t = 18
t = 18/9.81
t = 1.83 [s], we found the answer for B.
Now using the following equation.
where:
y = elevation [m]
Yo = initial elevation = 0
y = 18*(1.83) - 0.5*9.81*(1.83)²
y = 16.51 [m]