Answer:
Height from ground is 8 m where string will break
Explanation:
Let the string makes some angle with the vertical after some instant of time
So here we have
now by energy conservation we have
For string break down we have
Now height from the ground is given as
Answer:
1) p₀ = 0.219 kg m / s, p = 0, 2) Δp = -0.219 kg m / s, 3) 100%
Explanation:
For the first part, which is speed just before the crash, we can use energy conservation
Initial. Highest point
Em₀ = U = mg y
Final. Low point just before the crash
Emf = K = ½ m v²
Em₀ = Emf
m g y = ½ m v²
v = √ 2 g y
Let's calculate
v = √ (2 9.8 0.05)
v = 0.99 m / s
1) the moment before the crash is
p₀ = m v
p₀ = 0.221 0.99
p₀ = 0.219 kg m / s
After the collision, the car's speed is zero, so its moment is zero.
p = 0
2) change of momentum
Δp = p - p₀
Δp = 0- 0.219
Δp = -0.219 kg m / s
3) the reason is
Δp / p = 1
In percentage form it is 100%
The work-energy theorem states that the net work done by the forces on an object equals the change in its kinetic energy.
Answer:
is the initial velocity of tossing the apple.
the apple should be tossed after 
Explanation:
Given:
- velocity of arrow in projectile,
- angle of projectile from the horizontal,
- distance of the point of tossing up of an apple,
<u>Now the horizontal component of velocity:</u>
<u>The vertical component of the velocity:</u>
<u>Time taken by the projectile to travel the distance of 30 m:</u>
<u>Vertical position of the projectile at this time:</u>
<u>Now this height should be the maximum height of the tossed apple where its velocity becomes zero.</u>
is the initial velocity of tossing the apple.
<u>Time taken to reach this height:</u>
<u>We observe that </u>
<u> hence the time after the launch of the projectile after which the apple should be tossed is:</u>
Answer:
Explanation:
= Change in frequency = 2.1 Hz
= Frequency of source of sound = 440 Hz
= Maximum of the microphone
= Speed of sound = 343 m/s
= Time period = 2 s
We have the relation
Amplitude is given by
The amplitude of the simple harmonic motion is .
