Answer:
The angle of incidence is equal to the angle of reflection.
Explanation:
angle of incidence (i) = angle of reflection (r)
So if the angle of incidence was 45°, the angle of reflection would also be 45°.
"Fig is attacted with answer"
Answer:
a) d = 33.72 m
b) = 26 m/s
c) β = 71.08°
Explanation:
a)
When an object is thrown into the air under the effect of the gravitational force, the movement of the projectile is observed. Then it can be considered as two separate motions, horizontal motion and vertical motion. Both motions are different, so that they can be handled independently.
Given data:
time = t = 4.00 s
Height = h = 20 m
Angle = θ = 60°
Horizontal distance = d = ?
Using 2nd equation of motion
-20 = (4) + 0.5(-9.8)(4)²
(4) = 58.4
= 14.6 m/s
This is vertical component of velocity when the ball is on the roof. To calculate the Final velocity and horizontal component, we use
= / sinθ
= 14.6 / sin 60
= 16.86 m/s
= cosθ
= 16.86 cos 60
= 8.43 m/s
To calculate the horizontal distance
d = t
d = (8.43)(4)
d = 33.72 m
b)
We know the values of Landing angle, height of roof, time of flight. In part a, We calculate the landing velocity of the ball and also its horizontal and vertical component. As the ball followed the projectile path, and we know that in projectile motion the horizontal component of the velocity remain constant throughout his motion. So there is no acceleration along horizontal path.
So,
=
but the vertical component of velocity vary with and there is an acceleration along vertical direction which is equal to gravitation acceleration g.
So,
g = ( - ) / t
9.8 = 14.6 - ) / 4
= 24.6 m/s
=
=
= 26 m/s
c)
cos β = /
β = cos⁻¹ (8.43 / 26)
β = 71.08°
Answer:
a.) the speed at the bottom is greater for the steeperhill
Explanation:
since the energy at the bottom of the steeper hilis greater
As we can see from above that v is higher when h ishigher.
Answer:
Option A is correct.
The wires will be arranged in order of increasing resistance.
Explanation:
The resistance of a wire is given by
r = (ρl)/A
where r = resistance of the wire
ρ = resistivity of the wire
L = length of the wire
A = cross sectional area of the wire
Provided all the other parameters are constant, resistance is inversely proportional to cross sectional area
r ∝ (1/A)
And the the cross sectional Area of the wire increases with increase in thickness & decreases with thickness
So, decreasing thickness ----> Decreasing Cross sectional Area ----> Increasing resistance.
components of the speed of the coin is given as
now the time taken by the coin to reach the plate is given by
now in order to find the height
so it is placed at 1.52 m height