Answer:
The velocity of the skateboard is 0.774 m/s.
Explanation:
Given that,
The spring constant of the spring, k = 3086 N/m
The spring is stretched 18 cm or 0.18 m
Mass of the student, m = 100 kg
Potential energy of the spring, 
To find,
The velocity of the car.
Solution,
It is a case of conservation of energy. The total energy of the system remains conserved. So,






v = 0.774 m/s
So, the velocity of the skateboard is 0.774 m/s.
Hydrogen fuel cells is the answer
Answer:
2. at the lowest point
Explanation:
The motion of the pendulum is a continuous conversion between kinetic energy (KE) and gravitational potential energy (GPE). This is because the mechanical energy of the pendulum, which is sum of KE and GPE, is constant:
E = KE + GPE = const.
Therefore, when KE is maximum, GPE is minimum, and viceversa.
So, the point of the motion where the KE is maximum is where the GPE is minimum: and since the GPE is directly proportional to the heigth of the bob:

we see that GPE is minimum when the bob is at the lowest point,so the correct answer is
2. at the lowest point
Answer:
160 W
Explanation:
Power is the ratio of work to time:
(1600 J)/(10 s) = 160 J/s = 160 W
Answer:
Rs = 0.02008 Ω = 20.08 mΩ
Explanation:
The range of an ammeter can be increased by connecting a small shunt resistance to it in a series combination. This shunt resistance can be calculated by the following formula:

where,
= value of shunt resistance = ?
= current range of ammeter = 20 mA = 0.02 A
I = Required range of ammeter = 5 A
= Resistance of ammeter = 5 ohms
Therefore,

<u>Rs = 0.02008 Ω = 20.08 mΩ</u>