Answer:
6.32s
Explanation:
Given parameters:
Length of track and distance covered = 200m
Acceleration = 10m/s²
Unknown:
Time taken to cover the track = ?
Solution:
To solve this problem, we apply one of the motion equations as shown below:
S = ut + at²
S is the distance covered
t is the time taken
a the acceleration
u is the initial velocity
The initial velocity of Superman is 0;
So;
S = at²
200 = x 10 x t²
200 = 5t²
t² = 40
t = 6.32s
Answer:
b) d = 0.71 Km
Explanation:
Car kinematics
Car 1 moves with uniformly accelerated movement
Formula (1)
d: displacement in meters (m)
v₀: initial speed in m/s
vf: final speed in m/s
a: acceleration in m/s²
Equivalences:
1mile = 1609.34 meters
1 hour = 3600s
1km = 1000m
Known data
a = -0.5 m/s²
Distance calculation
We replace data in the Formula (1)
Answer:
The angle of incidence when the reflected ray is perpendicular to the incident ray = 45°
Explanation:
According to Snell's Law,
n₁ sin θ₁ = n₂ sin θ₂
When the angle between the incident ray and reflected ray is 90°, the angle of incidence is θ₁ and the angle of reflection, θ₂ = 90° - θ₁ and the index of refraction in the Snell's Law for both media would be the same, n₁ = n₂ = n
n sin θ₁ = n sin (90° - θ₁)
Note that from trigonometric relations,
Sin (90° - θ₁) = cos θ₁
n sin θ₁ = n cos θ₁
(sin θ₁)/(cos θ₁) = 1
tan θ₁ = 1
θ₁ = arctan 1 = 45°
Hope this Helps!!!
