All you need to know is that velocity is the derivative with respect to time of position.
Therefore: ds/dt = -32t +10
To know the velocity at t=2s you just need to plug t=2 for t in the equation above.
The correct answer D: all of the above
Answer:
the coin does not slide off
Explanation:
mass (m) = 5 g = 0.005 kg
distance (r) = 15 cm = 0.15 m
static coefficient of friction (μs) = 0.8
kinetic coefficient of friction (μk) = 0.5
speed (f) = 60 rpm
acceleration due to gravity (g) = 9.8 m/s^{2}
lets first find the angular speed of the table
ω = 2πf
ω = 2 x π x 60 x 
ω = 6.3 s^{-1]
Now lets find the maximum static force between the coin and the table so we can get the maximum velocity the coin can handle without sliding
static force (Fs) = ma
static force (Fs) = μs x Fn = μs x m x g
Fs = 0.8 x 0.005 x 9.8 = 0.0392 N
Fs = ma
0.0392 = 0.005 x a
a = 7.84 m/s^{2}
= a x r
= 7.84 x 0.15
Vmax = 1.08 m/s
ωmax = 
ωmax =
= 7.2 s^{-1}
now that we have the maximum angular acceleration of the table, we can calculate its maximum speed in rpm
Fmax = 
Fmax =
= 68.7 rpm
since the table is rotating at a speed less than the maximum speed that the static friction can hold coin on the table with, the coin would not slide off.
The answer is:
Hopping.
Explanation:
Hopping is done by taking off on one foot and landing back on that same foot. Hopping is done in shorter intervals, meaning you usually don't travel large distances through a single hop. Hopping is categorized as short leaps for its small distance covered singularly, and each hop is done only on one foot.
<em>(Think about if one of your feet/legs is injured or asleep. If you wanted to go from say the living room to the kitchen, but didn't wish to move that leg or foot, you would likely hop on one foot to get to the destination.)</em>
D
Because if an object is moving at a constant speed the force of friction must equal the applied (horizontal) force, and for it to be accelerating or decelerating, the force of friction and the applied force must be unequal