Answer:
300 N
Explanation:
We have three forces acting on the object:
- W = 1500 N, downward: the weight of the object
- F1 = 1200 N, upward: the force exerted by the first man
- F2, upward: the force exerted by the friend
In order to lift the object, the sum of the two forces F1 and F2 must be at least equal to the weight of the object W. Therefore we can write
And from this equation, we can find the magnitude of F2:
Explanation:
A worker picks up the bag of gravel. We need to find the speed of the bucket after it has descended 2.30 m from rest. It is case of conservation of energy. So,
h = 2.3 m
So, the speed of the bucket after it has descended 2.30 m from rest is 6.71 m/s.
Answer:
Explanation:
I is the moment of inertia of the pulley, α is the angular acceleration of the pulley and T is the tension in the rope. Let a is the linear acceleration.
The relation between the linear acceleration and the angular acceleration is
a = R α .... (1)
According to the diagram,
T x R = I x α
T x R = I x a / R from equation (1)
T = I x a / R² .... (2)
mg - T = ma .... (3)
Substitute the value of T from equation (2) in equation (3)
T is the acceleration in the system
Substitute the value of a in equation (2)
This is the tension in the string.
Answer:
acceleration of the rocket is given as
Explanation:
As we know that rocket starts from rest and then reach to final speed of 447 m/s after t = 1 min
so we have
so we have