Answer:
The force needed to slow down the car is, F = 67.5 N
Explanation:
Given data,
The mass of the car, m = 15 kg
The initial velocity of the car, V = 60 m/s
The final velocity of the car, v = 15 m/s
The time period of deceleration, t = 10 s
The difference in the momentum of the car is,
mV - mv = 15(60 - 15)
= 675 kg m/s
The rate of change in momentum of the car gives the force acting on it.
F = (mV - mu) / t
Substituting the values,
F = 675 / 10
= 67.5 N
Hence, the force needed to slow down the car is, F = 67.5 N
Answer:
Decreasing in altitude and increasing in velocity
Explanation:
The formula for potential energy is:

where m is mass, g is constant gravitational energy and h is the potential altitude.
The formula for kinetic energy is:

where v is the velocity
Since m,g are constant, to convert from potential energy to kinetic energy, h must decreases while v increases. For example dropping an object from a height.
Answer: Science is involved in cooking, eating, breathing, driving, playing, etc. The fabric we wear, the brush and paste we use, the shampoo, the talcum powder, the oil we apply, everything is the consequence of advancement of science. Life is unimaginable without all this, as it has become a necessity.
Explanation:
Radiocarbon saying assume the half life for radioistopes change over time. The half life of C -14 is 5730 years