Answer:
the answer is d
Explanation:
you get exhausted at the middle because it is steep.
Answer:
v = 0.489 m/s
Explanation:
It is given that,
Mass of a box, m = 1.5 kg
The compression in the spring, x = 6.5 cm = 0.065 m
Let the spring constant of the spring is 85 N/m
We need to find the velocity of the box (v) when it hit the spring. It is based on the conservation of energy. The kinetic energy of spring before collision is equal to the spring energy after compression i.e.


So, the speed of the box is 0.489 m/s.
Answer:
Suppose two objects of different masses are moving with different velocities in the same direction on a straght-line before collision. After collision, they stick together and move with common (the same) velocity
To develop this problem we will apply the considerations made through the concept of Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. At first the source is moving towards the observer. Than the perceived frequency at first

Where F is the actual frequency and v is the velocity of the ambulance
Now the source is moving away from the observer.

We are also so told the perceived frequency decreases by 11.9%



Equating,





Solving for V,
