1.
Answer:
a) It is less
Explanation:
By energy conservation we can say that initial potential energy of both child must be equal to the final kinetic energy of the two child.
Since initially they are at same height so we will say that initial potential energy will be given as
and MgH
so the child with greater mass has more energy and hence smaller child will reach with smaller kinetic energy
2.
Answer:
b. The two speeds are equal.
Explanation:
As we know by mechanical energy conservation law we have


since both child starts at same height so here they both will reach the bottom at same speed
3.
Answer:
c. The two accelerations are equal
Explanation:
Since we know that average acceleration of the motion is given as

since here initial and final speeds are same so they both must have same average acceleration here.
Note that
1 km/h = (1000 m)/(3600 s) = 0.27778 m/s
Initial velocity, v₁ = 25 km/h = 6.9444 m/s
Final velocity, v₂ = 65 km/h = 18.0556 m/s
Time interval, dt = 6 s.
Calculate average acceleration.
a = (v₂ - v₁)/dt
= (18.0556 - 6.9444 m/s)/(6 s)
= 1.852 m/s²
Answer:
The average acceleration is 1.85 m/s² (nearest hundredth)
Answer:
Explanation:
angular momentum of the putty about the point of rotation
= mvR where m is mass , v is velocity of the putty and R is perpendicular distance between line of velocity and point of rotation .
= .045 x 4.23 x 2/3 x .95 cos46
= .0837 units
moment of inertia of rod = ml² / 3 , m is mass of rod and l is length
= 2.95 x .95² / 3
I₁ = .8874 units
moment of inertia of rod + putty
I₁ + mr²
m is mass of putty and r is distance where it sticks
I₂ = .8874 + .045 x (2 x .95 / 3)²
I₂ = .905
Applying conservation of angular momentum
angular momentum of putty = final angular momentum of rod+ putty
.0837 = .905 ω
ω is final angular velocity of rod + putty
ω = .092 rad /s .
Answer:
Explanation:
Change in gravitational energy of the ball = mgh
5 mutiply 10 multiply 1.7 = 85J
Potential energy at height = Kinetic energy at bottom
KE= 85J
Velocity
v=5.83m/s