Answer:
Explanation:
Here the steady speed of the river water relative to ground is
Speed of the boy relative to still water is
Here we are considering +ve speed along along +ve x-axis and -ve speed along -ve x-axis
Therefore the speed of boy relative to the ground upstream is:
And the speed of boy relative to the ground downstream is:
The distance covered in upstream trip d₁=1.0km=1000m and the distance covered in downstream is d₂=1.0km=1000m
Since time taken by a person is to cover distance d with speed v given by:
The total time taken for one trip is:
Answer:
Explanation:
As we know that the 6 kg object was at rest initially
So here since net force on the system is zero
so the momentum of the system will always remains conserved
so we can say
now we know that
and the angle between the two objects is 60 degree
so we can say
now we can say that the speed of the third mass will be
now the total kinetic energy released in this system is given as
Answer:
Total time elapsed between the start and when he returns with the ball is 7.5s
Explanation:
From the question,
- The dog starts at the origin and runs forward at 6m/s for 1.5s. First, we will determine the distance covered while running forward.
From
Speed = Distance / Time
Distance = Speed × Time
Speed = 6m/s
Time = 1.5s
∴ Distance = 6m/s × 1.5s
Distance = 9m
That is, the dog covered a distance of 9m while running forward.
- The dog turns around and runs backward at 7m/s for 3s. Now, we will also determine the distance the dog covered backwards.
Distance = Speed × Time
Speed = 7m/s
Time = 3s
Distance = 7m/s × 3s
Distance = 21m
The dog's displacement from the origin is 21m - 9m = 12m
Now, to calculate how much time has elapsed between the start if the dog runs back to the origin at 4m/s, we will first determine the time the dog spent back to the origin and then add to the time spent for the first two distances.
To get back to the origin, the dog needs to cover 12m
From
Speed = Distance / Time
Time = Distance / Speed
Distance = 12m
Speed = 4m/s
∴ Time = (12m) / (4m/s)
Time = 3s
Therefore, the dog spent 3s to run back to the origin.
Hence, total time elapsed = 1.5s + 3s + 3s
Total time elapsed = 7.5s
Answer:
Electric potential, E = 2100 volts
Explanation:
Given that,
Electric field, E = 3000 N/C
We need to find the electric potential at a point 0.7 m above the surface, d = 0.7 m
The electric potential is given by :
V = 2100 volts
So, the electric potential at a point 0.7 m above the surface is 2100 volts. Hence, this is the required solution.
the object con tinues to fall but with NNO acceleration! notice that there is not net force if the upward and dowward forces are equal.
