Answer:
Explanation:
Using the conservation of the linear momentum P:
so:
where is the mass of kevin,
is the velocity of kevin before he grabs her brother,
is the velocity of her brother and him after grabs her brother and
is the velocity of both after the collition.
So, replacing the values and solving for Vk, we get:
Answer:
The maximum height reached is 4.63 m.
Explanation:
Given:
Initial speed of the man (u) = 31.0 m/s
Speed at the top of trajectory () = 29.5 m/s
Acceleration due to gravity (g) = 9.8 m/s²
When the man reaches the top of the trajectory, the vertical component of velocity becomes zero and hence only horizontal component of velocity acts on him.
Also, since there is no net force acting in the horizontal direction, the acceleration is zero in the horizontal direction from Newton's second law. Thus, the horizontal component of velocity always remains the same.
So, speed at the top of trajectory is nothing but the horizontal component of initial velocity.
Now, initial velocity can be rewritten in terms of its components as:
Where, are the initial horizontal and vertical velocities of the man.
Now, plug in the given values and simplify. This gives,
Now, we know that, for a projectile motion, the maximum height is given as:
Plug in the value from equation (1) and 9.8 for 'g' to solve for 'H'. This gives,
Therefore, the maximum height reached is 4.63 m.
Answer:
10 m/s
Explanation:
Given:
Amplitude of atomic vibrations (λ) = 10⁻⁹ cm = 10⁻⁹ × 10⁻² m = 10⁻¹¹ m [1 cm = 10⁻² m]
Frequency of the vibrations (f) = 10¹² Hz
In order to find the atom's maximum speed, we need to make use of the formula that relates speed, frequency and wavelength of the vibration.
Therefore, the formula for maximum speed is given as:
Now, plug in the values given and solve for speed 'v'. This gives,
Therefore, the atom's maximum speed due to thermal energy provided is 10 m/s.