Answer:
A)
B)
Explanation:
Given that
Force = F
Increase in Kinetic energy = 

we know that
Work done by all the forces =change in the kinetic energy
a)
Lets distance = d
We know work done by force F
W= F .d
F.d=ΔKE


b)
If the force become twice
F' = 2 F
F'.d=ΔKE'
2 F .d = ΔKE' ( F.d =Δ KE)
2ΔKE = ΔKE'

Therefore the final kinetic energy will become the twice if the force become twice.
Answer:
The charge on each plate is 0.0048 nC
Explanation:
for the distance between the plates d and given the area of plates, A, and ε = 8.85×10^-12 C^2/N.m^2, the capacitance of the plates is given by:
C = (A×ε)/d
=[(0.2304×10^-2)(0.2304×10^-2)×(8.85×10^-12))/(0.5974×10^-3)
= 7.86×10^-14 F
then if the plates are connected to a battery of voltage V = 61 V, the charge on the plates is given by:
q = C×V
= (7.86×10^-14)×(61)
= 4.80×10^-14 C
≈ 0.0048 nC
Therefore, the charge on each plate is 0.0048 nC.
Answer:
7.5secs
Explanation:
Using the equation of motion
v = u + at
v is the final velocity = 0m/s
u is the initial velocity = 9m/s
a is the deceleration = -1.2m/s²
t is the required time
Substitute;
0 = 9 + 1.2(t)
-9 = -1.2t
t = -9/-1.2
t = 7.5secs
hence it takes the child 7.5secs to stop
Answer:
3.80 m/s
Explanation:
Solution: From the question we have:
A 2.10 x 10^3 kg car starts from rest at the top of a 5.0 m long driveway that is sloped at 20 degrees with the horizontal.
average friction force of 4.0 x 10^3 N impedes the motion
To find out: find the speed of the car at the bottom of the driveway.
=>h = 5×sin20 = 1.71 m.
PE = mgh = 2100×9.8×1.71 = 35,192 J.
KE = PE-work done by frictional force
KE=PE-4000×5
0.5mV^2 = 35192 - 4000×5
1050V^2 = 15,192
V^2 = 14.47
V = 3.80 m/s.
Answer:
I believe C
Explanation:
i never learned this sorry