Answer:
t = 180 / 1.4 = 129 sec (time to swim horizontally across river)
S = 129 sec * V where V is speed of current and S is the distance he will be carried downstream
The problem does not specify V the speed of the river
Answer:
When a light wave goes through a slit, it is diffracted, which means the slit opening acts as a new source of waves. How much a light wave diffracts<em> (how much it fans out)</em> depends on the wavelength of the incident light. The wavelength must be larger than the width of the slit for the maximum diffraction. Thus, for a given slit, red light, because it has a longer wavelength, diffracts more than the blue light.
The corresponding relation for diffraction is
,
where
is the wavelength of light,
is the slit width, and
is the diffraction angle.
From this relation we clearly see that the diffraction angle
is directly proportional to the wavelength
of light—longer the wavelength larger the diffraction angle.
Answer:d
Explanation:
Given
First car is moving towards east with velocity 20 m/s

then it turns towards north then velocity is

suppose car takes t sec to change its path so average acceleration is given by


So average acceleration is towards North of west.
Answer:
ac = 3.92 m/s²
Explanation:
In this case the frictional force must balance the centripetal force for the car not to skid. Therefore,
Frictional Force = Centripetal Force
where,
Frictional Force = μ(Normal Force) = μ(weight) = μmg
Centripetal Force = (m)(ac)
Therefore,
μmg = (m)(ac)
ac = μg
where,
ac = magnitude of centripetal acceleration of car = ?
μ = coefficient of friction of tires (kinetic) = 0.4
g = 9.8 m/s²
Therefore,
ac = (0.4)(9.8 m/s²)
<u>ac = 3.92 m/s²</u>
Answer:
V' = 0.84 m/s
Explanation:
given,
Linear speed of the ball, v = 2.85 m/s
rise of the ball, h = 0.53 m
Linear speed of the ball, v' = ?
rotation kinetic energy of the ball

I of the moment of inertia of the sphere

v = R ω
using conservation of energy


Applying conservation of energy
Initial Linear KE + Initial roational KE = Final Linear KE + Final roational KE + Potential energy



V'² = 0.7025
V' = 0.84 m/s
the linear speed of the ball at the top of ramp is equal to 0.84 m/s