Answer:
Explanation:
a )
Moment of inertia will be of the wheel which is rotating about its centre .
So
I = 1/2 m R² ; m is mass and R is radius of the wheel
b )
If wheel is turned by small angle dθ , spring is stretched by length r dθ which is almost linear due to small value of dθ.
force developed in the spring = k x r dθ
torque of this force about the centre
= force x distance from the centre
= k x r dθ x r
Torque = k r² dθ
Answer:
4.8 m/s
Explanation:
When she catches the train,
- They will have travelled the same distance.and
- Their speeds will be equal
The formula for the distance covered by the train is
d = ½at² = ½ × 0.40t² = 0.20t²
The passenger starts running at a constant speed 6 s later, so her formula is
d = v(t - 6.0)
The passenger and the train will have covered the same distance when she has caught it, so
(1) 0.20t² = v(t - 6.0)
The speed of the train is
v = at = 0.40t
The speed of the passenger is v.
(2) 0.40t = v
Substitute (2) into (1)
0.20t² = 0.40t(t - 6.0) = 0.40t² - 2.4 t
Subtract 0.20t² from each side
0.20t² - 2.4t = 0
Factor the quadratic
t(0.20t - 2.4) = 0
Apply the zero-product rule
t =0 0.20t - 2.4 = 0
0.20t = 2.4
(3) t = 12
We reject t = 0 s.
Substitute (3) into (2)
0.40 × 12 = v
v = 4.8 m/s
The slowest constant speed at which she can run and catch the train is 4.8 m/s.
A plot of distance vs time shows that she will catch the train 6 s after starting. Both she and the train will have travelled 28.8 m. Her average speed is 28.8 m/6 s = 4.8 m/s.
Answer:
If a vertical line extending down from an object's CG extends outside its area of support, the object will topple
Explanation:
We can understand better this situation using a diagram with the forces acting on it.
In the attached image we can see that when the gravity center is bouncing outside from the area of the pedestal, the object will be out of balance and will fall.
The most likely element is silver
in second place is copper
<h2>
Answer:</h2>
Workdone = 601.33 Nm
<h2>
Explanation:</h2>
Workdone = Force(F) x horizontal distance(d).
Wordone = F x d
Where F is the horizontal component of the force
Force = 35 pounds
Recall that;
1 pound force = 4.4N
=> 35 pounds = 35 x 4.4N = 154N
=> Force = 154N
But since the rope makes a 10⁰ angle with the ground,
The horizontal component of the force F is Force x cos10⁰
=> F = 154 cos 10⁰
=> F = 154 x 0.9848
=> F = 151.66N
Horizontal distance (d) = 13 feet
Recall that;
1 foot = 0.305m
=> 13 feet = 13 x 0.305m = 3.965m
=> d = 3.965m
=> Substituting the values of F and d into the equation above, we have;
Workdone = F x d
Workdone = 151.66N x 3.965m
Workdone = 601.33Nm