EXPLORING SCIENCE

Exploring Science

Exploring Science

This assignment contains four questions along with their parts.

Q1 (a)(i):

In this case, when the diver is standing at the bottom, both his potential and kinetic energies are constant. When he starts climbing the stairs, his energy is consumed and is transferred into kinetic energy - given by the formula:

K.E. = 1/2 mv2

Where:

m= mass

v= velocity

Now the driver has climbed the stairs, and is standing on the diving board. At this point of time, his potential energy reaches the maximum value - given by the formula:

P.E. mgh

Where:

m= mass

g=gravitational acceleration

h=height of the diving board

Q1(a)(ii):

In this case, the diver is considered to be at a stationary position; hence his potential energy is at the maximum. While in the process of jumping, his total energy is being converted into kinetic energy, while the potential energy is decreasing.

Q1(a)(iii):

In this case, the individual has started to swim, thus the kinetic energy prevails. Although, there can be variation in an individual's acceleration during the process of swimming, but kinetic energy prevails.

Q1(b): A car drives along a dual carriageway at 96 km h-1. The driver sees a speed limit sign approaching and applies the brakes to decelerate to a speed of 48 km h-1. Given that the deceleration is 2.68 m s-2 find the distance over which the brakes are applied.

Data

Initial Velocity of the car = 96 Kmh-1

Final Velocity of the care = 48 Kmh-1

Decelaration = -2.68ms-2

Solution

As we know that:

1 kilometer per hour = 0.2777 meters per second (approx value up to 4 decimal places). Therefore:

Initial Velocity of the car = 96*0.2777 = 26.6592 ms-2

Final Velocity of the care = 48*0.2777 = 13.3296 ms-2

According to Newton's third equation of motion:

2as = vf2 - vi2

Calculating the distance's':

s = (vf2 - vi2) / 2a

s= (13.32)2 - (26.65)2 / 2(-2.68)

s = 177.42 ...