Answer:
Time, t = 12 minutes
Explanation:
It is given that,
A cyclist rides 16.0 km east, then 8.0 km west, then 8.0 km east, then 32.0 km west, and finally 11.2 km east. Let west direction is negative and east direction is positive. The displacement of the cyclist is :
d = 4800 m
Let us assumed that the average speed of the cyclist is, v = 24 km/h = 6.66667 m/s
Let t is the time taken by the cyclist to complete the trip. The velocity of an object is given by :
t = 719.99 seconds
t = 720 seconds
or
t = 12 minutes
So, the time taken by the cyclist to complete the trip is 12 minutes. Yes, the time taken by the cyclist to complete the trip is reasonable. Hence, this is the required solution.
Answer:
<em>B. 68.6m</em>
Explanation:
<u>Free Fall Motion
</u>
When a body is left to move in the air with no friction, the motion is ruled only by the force of gravity. The vertical distance a body travels in the air after a time t is
.
We know the egg takes 3.74 seconds to reach the ground. The height it was launched from is
The closest correct option is
B. 68.6m
F=ma, in this case your force=-883 N and mass = 90 kg. F/m=a therefore acceleration=-883/90=-9.81 m/s/s
Answer:
The shortest de Broglie wavelength for the electrons that are produced as photoelectrons is 0.81 nm
Explanation:
Given;
wavelength of ultraviolet light, λ = 270 nm
work function of the metal, φ = 2.3 eV = 2.3 x 1.602 x 10⁻¹⁹ J = 3.685 x 10⁻¹⁹ J
The energy of the ultraviolet light is given by;
The energy of the incident light is related to kinetic energy of the electron and work function of the metal by the following equation;
E = φ + K.E
K.E = E - φ
K.E = (7.362 x 10⁻¹⁹ J) - (3.685 x 10⁻¹⁹ J )
K.E = 3.677 x 10⁻¹⁹ J
K.E = ¹/₂mv²
mv² = 2K.E
velocity of the electron is given by;
the shortest de Broglie wavelength for the electrons is given by;
Therefore, the shortest de Broglie wavelength for the electrons that are produced as photoelectrons is 0.81 nm
