Answer
given,
height of window = 4 m
time taken to travel = 1 s
acceleration due to gravity = 9.8 m/s²
u = -0.905 m/s
initial velocity of ledge v = 0
now,
v² = u² + 2 a s
(-0.905)² = 0 + 2 × 9.8 ×s
s = 0.042 m
what is the average speed of (a) a car that travels 400m in 20s. and (b) an athlete who runs 1500m in 4 minutes
1 answer:
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Answer:
The tension force in the supporting cables is 7245N
Explanation:
There are two forces acting on the elevator: the force of gravity pointing down (+) with magnitude (elevator mass) x (gravitational acceleration), and the tension force of the cable pointing up (-) with an unknown magnitude F. The net force is the sum of these forces:
We are given the resulting acceleration along with the mass, i.e., we know the net force, allowing us to solve for F:
The tension force F in the supporting cables is 7245N
Hi there!
We can use the conservation of angular momentum to solve.
Recall the equation for angular momentum:
We can begin by writing out the scenario as a conservation of angular momentum:
= moment of inertia of the merry-go-round (kgm²)
= angular velocity of merry go round (rad/sec)
= final angular velocity of COMBINED objects (rad/sec)
= moment of inertia of boy (kgm²)
= angular velocity of the boy (rad/sec)
The only value not explicitly given is the moment of inertia of the boy.
Since he stands along the edge of the merry go round:
We are given that he jumps on the merry-go-round at a speed of 5 m/s. Use the following relation:
Plug in the given values:
Now, we must solve for the boy's moment of inertia:
Use the above equation for conservation of momentum: