Answer:
The rock's final speed at the required altitude will be 42.24 m/s.
Explanation:
Let's start by finding the initial vertical speed.
Vertical Speed = 1.61 * Sin (53.2°)
Vertical Speed = 0.8 m/s
We want to know the speed of the rock when it is at an altitude of 91 km.
The total displacement of the rock from its starting position will thus be equal to -91 km
We can use this in the following equation:
t = 4.3918 seconds
Thus it takes 4.3918 seconds to reach the required altitude. We can now find the speed as follows:
Thus the rock's final speed at the required altitude will be 42.24 m/s.
The correct graph is <u>D</u>.
The graph <em>A</em> is a straight line sloping downwards and it shows that the speed of the body is decreasing at a constant rate. Therefore, this s a graph of a body that is under a constant deceleration.
The graph B is a straight line which slopes upwards. Hence the graph shows that the speed of the body increases at a constant rate. Therefore, this is a graph of a body that is accelerating at a constant rate.
The graph C is curved line, which curves upwards. The slope of the curve increases with time. This is therefore, a graph of a body which is under increasing acceleration.
The graph D, however is a straight line parallel to the time axis. The speed of the body has the same value at all times. Therefore, Graph D is the graph which shows the motion of a body with constant speed.
Answer:
Total internal reflection is going on. The refractive index of water is about 1.3, so sin 90/sin r=1/sinr=1.3. So the fish can only see objects outside the water within about 50 degrees of the vertical
Answer:
60 kg m/s
Explanation:
Let 
be the acceleration of the object.
As the acceleration of the object is constant, so
Given that applied force, F=6.00 N,
From Newton's second law, we have
,
[from equation (i)]
[given that time, t=10 s and F=6 N]
Here mv is the final momentum of the object and mu is the initial momentum of the object.
So, the change in the momentum of the object is mv-mu.
Hence, the change in the momentum of the object is 60 kg m/s.
