Answer:
30-N
Explanation:
Because they are both acting on an object going opposite directions, then you simply subtract the 15 from 45 as 45N of force is stronger than 15N of force.
Explanation:
It is given that,
Mass of the football player, m = 92 kg
Velocity of player, v = 5 m/s
Time taken, t = 10 s
(1) We need to find the original kinetic energy of the player. It is given by :


k = 1150 J
In two significant figure, 
(2) We know that work done is equal to the change in kinetic energy. Work done per unit time is called power of the player. We need to find the average power required to stop him. So, his final velocity v = 0
i.e. 

P = 115 watts
In two significant figures, 
Hence, this is the required solution.
It is called observation because you observe with your nose by semlling things your eyes by looking at things your ears by hearing things your tongue by tasting things and your hands by feeling things
1. First blank is A. Conductors
Second blank is D. Insulators
2. C. Heat
A) change in ht after 180m = 180 * sin(4-deg.) = 12.56m
net work done by gravity on the cyclist = mass * gravity * height diff.
= 85 * 9.8 * 12.56
= 10470J
= 10.5kJ
B) Kinetic energy = 1/2 * mass * vel.^2 = work done by gravity = 10470J
vel.^2 = 10470 * 2 / 85 = 246.4
vel. = 15.7m/s