Answer: Tension = 53.6N
Explanation:
Given that
Height h = 1 m
Time t = 1.7 s.
Mass m = 5.1 kg
From the equation of the motion we can get the acceleration of the elevator:
h = X0+ V0t + at2/2;
Th elevator starts from rest with a constant upward acceleration. Initial velocity Vo = 0, also Xo = 0; thus
a = 2h/t2 = 2 × 1/1.7^2
a = 0.69 m/s2.
Then we can find the tension in the cord by using the formula
T = mg + ma
= 5.1 (9.8 + 0.69)
= 5.1 × 10.5
= 53.6N
Answer:
What is the pressure transmitted in the liquid on a hydraulic pump where an elephant with a weight of 40 000 N is placed on top of the large piston with an area of 40 m2. The small piston area is 4 m2.
Answer:
The magnitude of the large object's momentum change is 3 kilogram-meters per second.
Explanation:
Under the assumption that no external forces are exerted on both the small object and the big object, whose situation is described by the Principle of Momentum Conservation:
(1)
Where:
, 
- Initial and final momemtums of the small object, measured in kilogram-meters per second.
, 
- Initial and final momentums of the big object, measured in kilogram-meters per second.
If we know that 
, 
and 
, then the final momentum of the big object is:
The magnitude of the large object's momentum change is:
The magnitude of the large object's momentum change is 3 kilogram-meters per second.
Answer:
a) τ = 0.672 N m
, b) θ = 150 rad
, c) W = 100.8 J
Explanation:
a) for this part let's start by finding angular acceleration, when the angular velocity stops it is zero (w = 0)
w = w₀ + α t
α = -w₀ / t
α = 120 / 2.5
α = 48 rad / s²
The moment of inertia of a cylinder is
I = ½ M R²
Let's calculate the torque
τ = I α
τ = ½ M R² α
τ = ½ 2.8 0.1² 48
τ = 0.672 N m
b) we look for the angle by kinematics
θ = w₀ t + ½ α t2
θ = ½ α t²
θ = ½ 48 2.5²
θ = 150 rad
c) work in angular movement
W = τ θ
W = 0.672 150
W = 100.8 J
Answer:
Explanation:
We shall apply law of conservation of momentum .
total Initial momentum =
7.5 x 8.85 = 66.375 kg m / s
total mass = 7.5 + 61.5 = 69 kg , common velocity of ball and performer be v
Total momentum = 69 v
69 v = 66.375
v = 66.375 / 69
= .962 m /s .
