Answer:
v = 7.4 m/s
Explanation:
Given that,
Mass if a volleyball, m = 5 kg
The ball reaches a height of 2.8 m
We need to find how fast the ball is going as it bumped into the air. Ket the velocity is v. Using the conservation of energy to find it as follows :
So, the required speed is 7.4 m/s. Hence, the correct option is (b).
Answer:
a) The velocity is 2.94m/s
b) 0.441
Explanation:
a) Assume gravity is 9.8m/s^2
Use the equation below to solve for the velocity at 0.30 seconds
,
vf =unknown velocity vi= initial velocity vi=0m/s a= 9.8m/s^2 t=0.30seconds
Step 1: Substitute the variables with the knowns
Step 2: Solve
b)
Use the equation below to solve for the displacement at 0.30 seconds
Step 1: Substitute the same variables with the knowns
Note that vi*t=0 as vi=0m/s
Step 2: Solve
x=0.441m
Answer:
Tension in the supporting cable is = 4,866 N ≅4.9 KN
Explanation:
First of all, we need to understand that tension is a force, so the motion law
F = Ma applies perfectly.
From Newtons third law of motion, action and reaction are equal and opposite. This means that the force experienced by the elevator, is equal to the tension experienced by the spring.
Parameters given:
Mass of load = 1650 kg
Acceleration of load = ?
The acceleration of the load can be obtained by diving the change in velocity by the time taken. But we need to know the time taken for the motion to 41 m.
Time taken = distance covered / velocity
= = 3.73 seconds
∴Acceleration = ( initial velocity - final velocity )/ time taken
Note: Final velocity is = 0 since the body came to a rest.
Acceleration = = 2.95m/
Force acting on the cable = mass of elevator × acceleration of elevator
= 1650 × 2.95 = 4869.5 kg ≅ 4.9 KN
Answer:
The second ball
Explanation:
Both balls are under the effect of gravity, accelerating with exactly the same value. The first ball is dropped, therefore its initial velocity is zero. Since the second ball has horizontal and vertical velocity components, its initial velocity is given by:
The vertical component is zero, however, it has a horizontal velocity, so its initial speed is not zero, therefore the secong ball has the greater speed at ground level.