Jay bought a toy car. To make the car move, he must turn a key attached to a spring. Turning the key winds the spring tight. The
2 answers:
Answer:
Elastic potential energy into kinetic energy
Explanation:
Initially, all the energy is stored in the spring, which is compressed. This energy is called elastic potential energy, and it is equal to
where k is the spring constant and x is the compression of the spring. When the key is turned, the spring is released, and all this energy is converted into kinetic energy, which is the energy due to the motion of the car. The equation that gives this energy is
where m is the mass of the car and v is the speed of the car.
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Answer:
Position A/Position E
,
Position B/Position D
,
, for
Position C
,
Explanation:
Let suppose that ball-Earth system represents a conservative system. By Principle of Energy Conservation, total energy () is the sum of gravitational potential energy (
) and translational kinetic energy (
), all measured in joules. In addition, gravitational potential energy is directly proportional to height (
) and translational kinetic energy is directly proportional to the square of velocity.
Besides, gravitational potential energy is increased at the expense of translational kinetric energy. Then, relative amounts at each position are described below:
Position A/Position E
,
Position B/Position D
,
, for
Position C
,
Explanation:
It is given that,
Mass of golf club, m₁ = 210 g = 0.21 kg
Initial velocity of golf club, u₁ = 56 m/s
Mass of another golf ball which is at rest, m₂ = 46 g = 0.046 kg
After the collision, the club head travels (in the same direction) at 42 m/s. We need to find the speed of the golf ball just after impact. Let it is v.
Initial momentum of golf ball,
After the collision, final momentum
Using the conservation of momentum as :
v = 63.91 m/s
So, the speed of the golf ball just after impact is 63.91 m/s. Hence, this is the required solution.