Answer:
45 degrees
Explanation:
The textbooks say that the maximum range for projectile motion (with no air resistance) is 45 degrees.
Answer:
Explanation:
a )
Time to reach the speed of 20 m/s with an acceleration of 2 m/s² can be calculated as follows .
v = u + a t
20 = 0 + 2 t
t = 20 /2 = 10 s .
Total time = 10 s + 20 s + 5 s = 35 s .
b) Average velocity = Total distance travelled / total time
Distance travelled in first 10 s
S₁ = ut + 1/2 a t²
= 0 + .5 x 2 x 10²
= 100 m
Distance travelled in next 20 s
S₂= 20s x 20 m/s = 400 m
Distance travelled in last 5 s .
deceleration in last 5 s
v = u + at
0 = 20 m/s + a x 5
a = - 4 m/s²
v² = u² - 2 a s
0 = (20 m/s)² - 2 x 4 m/s² x s
s = 50 m
S₃ = 50 m
Total distance = S₁ + S₂ + S₃
= 100 m + 400 m + 50 m
= 550 m .
Average velocity = 550 m / 35 s
= 15.71 m /s .
The question is incomplete. You dis not provide values for A and B. Here is the complete question
Light in the air is incident at an angle to a surface of (12.0 + A) degrees on a piece of glass with an index of refraction of (1.10 + (B/100)). What is the angle between the surface and the light ray once in the glass? Give your answer in degrees and rounded to three significant figures.
A = 12
B = 18
Answer:
18.5⁰
Explanation:
Angle of incidence i = 12.0 + A
A = 12
= 12.0 + 12
= 14
Refractive index u = 1.10 + B/100
= 1.10 + 18/100
= 1.10 + 0.18
= 1.28
We then find the angle of refraction index u
u = sine i / sin r
u = sine24/sinr
1.28 = sine 24 / sine r
1.28Sine r = sin24
1.28 sine r = 0.4067
Sine r = 0.4067/1.28
r = sine^-1(0.317)
r = 18.481
= 18.5⁰
Answer:
E = 16.464 J
Explanation:
Given that,
Mass of tetherball, m = 0.8 kg
It is hit by a child and rises 2.1 m above the ground, h = 21. m
We need to find the maximum gravitational potential energy of the ball. The formula for the gravitational potential energy is given by :
E = mgh
g is acceleration due to gravity
E = 0.8 kg × 9.8 m/s² × 2.1 m
= 16.464 J
So, the maximum potential energy of the ball is 16.464 J.
