Answer:
Answer for A
Explanation:
F1=GmM/r1^2
If r2 becomes r2=5r
F2=GmM/(25r^2)
Multiply with 25 gives to maintain the same force
I.e.,25F2=F1
F2=G(25m)M/25r^2=F1
By the factor 25 would change to increase to same.
Answer:
F > W * sin(α)
Explanation:
The force needed for the box to start sliding up depends on the incline (α).
The external forces acting on the box would be the weight, the normal reaction and the lifting force that is applied to make it slide up.
These forces can be decomposed on their normal and tangential (to the slide plane) components.
The weight will be split into
Wn = W * cos(α) (in normal direction)
Wt = W * sin(α) (in tangential direction)
The normal reaction will be alligned with the normal axis, and will be equal to -Wn
N = -W* cos(α) (in normal direction)
To mke the box slide up, a force must be applied, that is opposite to the tangential component of the weight and at least a little larger
F > |-W * sin(α)| (in tangential direction)
M = mass of the whale = 1000 kg
m = mass of the seal = 200 kg
V = initial velocity of whale before collision with the seal = 6.0 m/s
v = initial velocity of the seal before collision with the whale = 0 m/s
V' = final velocity of two sea creatures after collision = ?
Using conservation of momentum
M V + m v = (M + m) V'
inserting the above values in the equation
(1000 kg) (6.0 m/s) + (200 kg) (0 m/s ) = (1000 kg + 200 kg) V'
6000 kgm/s + 0 kgm/s = (1200 kg) V'
V' = (6000 kgm/s ) /(1200 kg)
V' = 5 m/s
The radar device determines the vehicle's instantaneous speed.
I would argue that the purpose of the device is not to determine
whether individuals are driving safely. They only determine whether
individuals are driving within legal speed limits. There's much more
to 'safe' driving than that, but the radar gun can't detect it.
