Answer:
7200 N/m
Explanation:
Metric unit conversion
100g = 0.1 kg
5 cm = 0.05 m
50 cm = 0.5 m
As the block is released from the spring and travelling to height h = 1.5m off the ground, the elastics energy is converted to work of friction force and the potential energy at 1.5 m off the ground
The work by friction force is the product of the force F = 15N itself and the distance s = 0.5 m

Let g = 10 m/s2. The change in potential energy can be calculated as the following:

Therefore, as elastic energy is converted to potential energy and work of friction:



Answer:
Speed of the wreck after the collision is 65 km/h
Explanation:
When a car hits truck and sticks together, the collision would be totally inelastic. Since the both the vehicles locked together, they have the same final velocity.
Mass of car 
Mass of truck 
Initial speed of the car 
Initial speed of the truck 
The final velocity of the wreck will be

since final speed are same, 


Answer:
From C to D, kinetic energy is transformed into gravitational potential energy.
i think
The reason as to why technicians shouldn’t use oxygen or
compressed air in pressurizing appliances in cases of checking leaks because
when this is mixed with the compressor oil or other refrigerants, this will
likely cause explosion because of the oxygen or compressed air mixed to it.
Answer:
Check the first and the third choices:
<u><em /></u>
- <u><em>a. The temperature of a gas is directly proportional to its volume</em></u>
- <u><em>b. The temperature-to-volume ratio of a gas is constant.</em></u>
Explanation:
Rewrite the table for better understanding:
Temperature of gas (K) Volume of gas (L)
298 4.55
315 4.81
325 4.96
335 ?
Calculate the ratios temperature to volume with 3 significant figures:
Then, those numbers show a <u><em>constant temperature-to-volume ratio</em></u>, which may be expressed in a formula as:
- Temperature / Volume = constant, which is a directly proportional variation (the volume increases in a constant proportion to the increase of the temperature).
Hence, the correct choices are:
- The temperature of a gas is directly proportional to its volume (first statement), and
- The emperature-to-volume ratio of a gas is constant (third statement).