Answer:
Explanation:
For rolling up or down an incline plane , the acceleration or deceleration of the rolling body is given by the following expression
a = g sinθ / (1 + k²/r² )
where k is radius of gyration of rolling body and θ is angle of inclination
a = g sin15 / ( 1 + 1 ) [ for hoop k = r ]
a = 9.8 x .2588 / 2
= 1.268 m / s²
a )
Let s be the distance up to which it goes
v² = u² - 2as
0 = 3.3² - 2 x 1.268 s
s = 4.3 m
b ) Let time in going up be t₁
v = u - at₁
0 = 3.3 - 1.268 t₁
t₁ = 2.6 s
Time in going down t₂
s = 1/2 a t₂²
4.3 = .5 x 1.268 t₂²
t₂ = 2.60
Total time
= t₁ +t₂
= 2.6 + 2.6
= 5.2 s
Answer:
a= (-g) from the moment the ball is thrown, until it stops in the air.
a = (0) when the ball stops in the air.
a = (g) since the ball starts to fall.
Explanation:
The acceleration is <em>(-g)</em> <em>from the moment the ball is thrown, until it stops in the air</em> because the movement goes in the opposite direction to the force of gravity. In the instant <em>when the ball stops in the air the acceleration is </em><em>(0)</em> because it temporarily stops moving. Then, <em>since the ball starts to fall, the acceleration is </em><em>(g)</em><em> </em>because the movement goes in the same direction of the force of gravity
<span>Mass of the electron = 9.1 x 10 ^ -28g = 9.1 x 10 ^ -31kg
Velocity of the electron = 1.7 x 10 ^ 4
We have Planck Constant h = 6.626 x 10 ^ -34
Wavelength of the electron w = h/mv
w = 6.626 x 10 ^ -34 / ((9.1 x 10 ^ -31)(1.7 x 10 ^ 4))
= 6.626 x 10 ^ -34 / 15.47 x 10 ^ -27
= 0.428312 x 10 ^ -7
= 4.28 x 10 ^ -8 m</span>
Answer:
The average velocity is 40km/h.
Explanation:
The average velocity is 
, where 
is the distance traveled and 
the time elapsed.
The distance traveled is clearly 80km since it's all done in the same direction, we only need to know the time elapsed. For this we calculate the time elapsed on the first part, and add it to the time elapsed on the second part using always the formula 
, where v is the velocity on each part, which is constant.
The time elapsed for the first part is 
, and the time elapsed for the second part is 
, giving us a total time of 
=2h.
Finally, we can calculate the average velocity: 
.
Answer:
(a): The normal force on the car from the track when the car's speed is v= 7.6 m/s is FN= -6696 N.
(b): The normal force on the car from the track when the car's speed is v= 17 m/s is FN= 8912.7 N.
Explanation:
m= 1080 kg
r= 16m
v1= 7.6 m/s
v2= 17 m/s
g= 9.81 m/s²
v1= w1*r
w1= v1/r
w1= 0.475 rad/s
ac1= w1² * r
ac1= 3.61 m/s²
FN= m * (ac1 - g)
FN= -6696 N (a)
-----------------------------------------------------
v2= w2*r
w2= v2/r
w2= 1.06 rad/s
ac2= w2² * r
ac2= 18.06 m/s²
FN= m * (ac2 - g)
FN= 8912.7 N (b)
