A roofer drops a nail that hits the ground traveling at 26 m/s. How fast was the nail traveling 1 second before it hits the grou
1 answer:
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False.
The mass of a softball is approximately 200 g (0.2 kg), while the knees are located approximately at 30 cm (0.3 m) from the ground. It means that the gravitational potential energy of the ball when it is dropped is
This corresponds to the total mechanical energy of the ball at the moment it is dropped, because there is no kinetic energy (the ball starts from rest). Then the ball is dropped, and just before it hits the ground, all this energy is converted into kinetic energy: but energy cannot be created, so its final kinetic energy cannot be greater than 0.6 J.
The mass of a softball is approximately 200 g (0.2 kg), while the knees are located approximately at 30 cm (0.3 m) from the ground. It means that the gravitational potential energy of the ball when it is dropped is
This corresponds to the total mechanical energy of the ball at the moment it is dropped, because there is no kinetic energy (the ball starts from rest). Then the ball is dropped, and just before it hits the ground, all this energy is converted into kinetic energy: but energy cannot be created, so its final kinetic energy cannot be greater than 0.6 J.
Answer:
The critical stress required for the propagation of an initial crack = 21.84 M pa
Explanation:
Given data
Modulus of elasticity E = 225 ×
Specific surface energy for magnesium oxide is = 1
Crack length (a) = 0.3 mm = 0.0003 m
Critical stress is given by =
-------- (1)
⇒ 2 E = 2 × 225 ×
× 1 = 450 ×
⇒ a = 3.14 × 0.0003 = 0.000942
⇒ Put these values in equation 1 we get
⇒ =
⇒ = 4.77 ×
⇒ = 2.184 ×
⇒ = 21.84
⇒ = 21.84 M pa
This is the critical stress required for the propagation of an initial crack.
Answer:
(A) Time period T = 6.28 SEC
(B) At highest point fore is - 575.83 N
(B) At lowest point force is 1050.97 N
Explanation:
We have given that mass m = 83 kg
Radius r = 13 m
Speed v = 6.10 m/sec
(A) Time period of the motion is given by
(b) Net force is given by
Force due to gravity
At highest point
(B) At lowest point