Answer:
Time, t = 2 seconds
Explanation:
Given the following data;
Mass, m = 50 kg
Initial velocity, u = 0 m/s (since it's starting from rest).
Final velocity, v = 8 m/s
Force, F = 200 N
To find the time, we would use the following formula;
Making time, t the subject of formula, we have;
Substituting into the formula, we have;
Time, t = 2 seconds
Answer:
d. 100.0 J
Explanation:
To solve this problem we must use the theorem of work and energy conservation. This tells us that the mechanical energy in the final state is equal to the mechanical energy in the initial state plus the work done on a body. In this way we come to the following equation:
E₁ + W₁₋₂ = E₂
where:
E₁ = mechanical energy at state 1. [J] (units of Joules)
E₂ = mechanical energy at state 2. [J]
W₁₋₂ = work done from 1 to 2 [J]
We have to remember that mechanical energy is defined as the sum of potential energy plus kinetic energy.
The energy in the initial state is zero, since there is no movement of the hockey puck before imparting force. E₁ = 0.
The Work on the hockey puck is equal to:
W₁₋₂ = 100 [J]
100 = E₂
Since the ice rink is horizontal there is no potential energy, there is only kinetic energy
Ek = 100 [J]
It can be said that the work applied on the hockey puck turns into kinetic energy
If the intelligent aliens on that distant planet could receive our signal, and then reply to us INSTANTLY with no delay, then our Scientists on Earth would hear the response <em>eight years after</em> they sent their original greeting.
Light and radio waves both travel through space at the same speed. If our scientists sent a radio transmission to that distant planet, it would take four years for the radio message to get there and be heard. Any response would take four years to travel back to us. If the aliens didn't dilly-dally and sent their response immediately, the round trip would total up to eight years.
Impulse equals to the force into the actual time period of the applied force . thus the force here given is 245.300 N and time is 0.05 thus the impulse is 12.265 Ns
- Unlike charges attract .
- like charges repel .
There are two types of charges
Namely :
On loosing electrons , a neutral body acquires positive charge .
On gaining electrons , a neutral body acquires negative charge .
The amount of charge present in a body , either positive or negative , is expressed in terms of an integral number of charge of an electron , which is considered the elementary entity of an electric charge .
