Missing graph. I attach it in the answer.
In a uniformly accelerated motion, the velocity at time t is given by:

where a is the acceleration and t is the time.
Given the previous equation, if we plot v(t) versus t, we find a straight line; moreover, a (the acceleration) represents the slope of the curve.
Looking at the graph, we see that when the time goes from 10 s to 20 s, the velocity increases from 4 m/s to 6 m/s. Therefore the slope of the curve is

and this corresponds to the acceleration.
So, the correct answer is <span>
0.2 m/s2.</span>
Explanation:
The total energy of the system remains conserved. It just converts from one form of energy to another.
The battery of the cell phone contains chemicals. As the electricity is passed through the cell phone, the electrical energy is converted to chemical energy. As she notices that the phone is warm and after the battery has been fully charged and the student unplugs her cell phone, the phone vibrates when a message arrives, this shows the conversion of chemical energy to mechanical energy, thermal energy etc.
Hence, we can say that the correct option is (b).
Answer:
E = 8.5 * 10^6 V/m
Explanation:
In general we have the following relation between the Electric Field and the Elecric Potential:

Due to the vector nature of the electric filed, we can only know the mean Electric field E across the membrane, and take it out from the integral, that is:
E = (ΔV)/L
Where L is the thickness of the membrane and ΔV is the potential difference.
Therefore:
E = 8.53933*10^6 V/m
rounding to the first tenth:
E = 8.5 * 10^6 V/m
Answer:
6.13 s
219 N
Explanation:
Newton's law in the x direction:
∑F = ma
150 cos 30° N − 50 N = (30 kg) a
a = 2.66 m/s²
Δx = v₀ t + ½ at²
(50 m) = (0 m/s) t + ½ (2.66 m/s²) t²
t = 6.13 s
Newton's law in the y direction:
∑F = ma
Fn + 150 sin 30° N − (30 kg) (9.8 m/s²) = 0
Fn = 219 N