Answer:
4 N to the right
Explanation:
For the object in this problem, we have 2 forces acting on it:
- A force of 2 N, to the right
- A force of 2 N, to the right
The two forces are in line: this means that the two vectors can be simply added by calculating their algebraic sum.
If we take right as positive direction, the two forces can be written as
F1 = +2 N
F2 = +2 N
So, the net force will be
And the positive sign means the direction is to the right.
D. Using a fixed-pulley system
Answer:
576 joules
Explanation:
From the question we are given the following:
weight = 810 N
radius (r) = 1.6 m
horizontal force (F) = 55 N
time (t) = 4 s
acceleration due to gravity (g) = 9.8 m/s^{2}
K.E = 0.5 x MI x ω^{2}
where MI is the moment of inertia and ω is the angular velocity
MI = 0.5 x m x r^2
mass = weight ÷ g = 810 ÷ 9.8 = 82.65 kg
MI = 0.5 x 82.65 x 1.6^{2}
MI = 105.8 kg.m^{2}
angular velocity (ω) = a x t
angular acceleration (a) = torque ÷ MI
where torque = F x r = 55 x 1.6 = 88 N.m
a= 88 ÷ 105.8 = 0.83 rad /s^{2}
therefore
angular velocity (ω) = a x t = 0.83 x 4 = 3.33 rad/s
K.E = 0.5 x MI x ω^{2}
K.E = 0.5 x 105.8 x 3.33^{2} = 576 joules
Answer: 1339.5 joules
Explanation:
Gravitational potential energy, GPE is the energy possessed by the jumper as he moves against gravity.
Thus, GPE = Mass m x Acceleration due to gravity g x Height h
Since Mass = 67kg
g = 9.8m/s^2
h = 2.04 metres
Thus, GPE = 67kg x 9.8m/s^2 x 2.04m
GPE = 1339.5 joules
Thus, the gravitational potential energy at the highest point is 1339.5 joules
