Answer:
a) -4 N
b) +4 N
Explanation:
Draw a free body diagram for each block.
For the large block, there are 2 forces: 12 N pushing to the right, and F pushing to the left.
For the small block, there is 1 force, F pushing to the right.
There are also weight and normal forces in the vertical direction, but we can ignore those.
Sum of forces on the large block in the x direction:
∑F = ma
12 − F = 4a
Sum of forces on the small block in the x direction:
∑F = ma
F = 2a
2F = 4a
Substitute:
12 − F = 2F
12 = 3F
F = 4
The small block pushes on the large block 4 N to the left (-4 N).
The large block pushes on the small block 4 N to the right (+4 N).
Answer:
15.5 seconds
Explanation:
Apply Newton's second law:
∑F = ma
-12500 + 9200 = (12000) a
a = -0.275 m/s²
v = at + v₀
0 = (-0.275) t + 4.25
t = 15.5 s
It takes the boat 15.5 seconds to stop.
Probably because of the drag coefficient and the density of the liquid.
Answer:
1.81 x 10^-4 m/s
Explanation:
M = 98700 kg
m = 780 kg
d = 201 m
Let the speed of second asteroid is v.
The gravitational force between the two asteroids is balanced by the centripetal force on the second asteroid.
Where, G be the universal gravitational constant.
G = 6.67 x 10^-11 Nm^2/kg^2
v = 1.81 x 10^-4 m/s
Answer:
Explanation:
Firstly, when you measure the voltage across the battery, you get the emf,
E = 13.0 V
In order to proceed we have to assume that the voltmeter offers no loading effect, which is a valid assumption since it has a very high resistance.
Secondly, the wires must be uniform. So the resistance per unit length is constant (say z). Now, even though the ammeter has very little resistance it cannot be ignored as it must be of comparable value/magnitude when compared to the wires. This is can seen in the two cases when currents were measured. Following Ohm's law and the resistance of a length of wire being proportional to it's length, we should have gotten half the current when measuring with the 40 m wire with respect to the 20 m wire (
). But this is not the case.
Let the resistance of the ammeter be r
Hence, using Ohm's law we get the following 2 equations:
.......(1)
......(2)
Substituting the value of r from (2) in (1), we have,
which simplifying gives us, 
(which is our required solution)
putting the value of z in either (1) or (2) gives us, r = 0.5325 
